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.
13124 vulnerabilities reference this CWE, most recent first.
GHSA-FWFM-F7PG-RQ6R
Vulnerability from github – Published: 2023-12-12 03:31 – Updated: 2023-12-14 21:31SAP Master Data Governance File Upload application allows an attacker to exploit insufficient validation of path information provided by users, thus characters representing ‘traverse to parent directory’ are passed through to the file APIs. As a result, it has a low impact to the confidentiality.
{
"affected": [],
"aliases": [
"CVE-2023-49058"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-12-12T01:15:12Z",
"severity": "LOW"
},
"details": "SAP Master Data Governance File Upload application\u00a0allows an attacker to exploit insufficient validation of path information provided by users, thus characters representing \u2018traverse to parent directory\u2019 are passed through to the file\u00a0APIs. As a result, it has a low impact to the\u00a0confidentiality.\n\n",
"id": "GHSA-fwfm-f7pg-rq6r",
"modified": "2023-12-14T21:31:13Z",
"published": "2023-12-12T03:31:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-49058"
},
{
"type": "WEB",
"url": "https://me.sap.com/notes/3363690"
},
{
"type": "WEB",
"url": "https://www.sap.com/documents/2022/02/fa865ea4-167e-0010-bca6-c68f7e60039b.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-FWFV-5XMW-XX69
Vulnerability from github – Published: 2022-05-17 05:47 – Updated: 2022-05-17 05:47Absolute path traversal vulnerability in curl 7.20.0 through 7.21.1, when the --remote-header-name or -J option is used, allows remote servers to create or overwrite arbitrary files by using \ (backslash) as a separator of path components within the Content-disposition HTTP header.
{
"affected": [],
"aliases": [
"CVE-2010-3842"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2010-10-28T00:00:00Z",
"severity": "MODERATE"
},
"details": "Absolute path traversal vulnerability in curl 7.20.0 through 7.21.1, when the --remote-header-name or -J option is used, allows remote servers to create or overwrite arbitrary files by using \\ (backslash) as a separator of path components within the Content-disposition HTTP header.",
"id": "GHSA-fwfv-5xmw-xx69",
"modified": "2022-05-17T05:47:12Z",
"published": "2022-05-17T05:47:12Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2010-3842"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=642642"
},
{
"type": "WEB",
"url": "http://curl.haxx.se/docs/adv_20101013.html"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/39532"
},
{
"type": "WEB",
"url": "http://securitytracker.com/id?1024583"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2010/10/13/1"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2010/10/13/4"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2010/10/13/5"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-FWG4-PX6F-6FJ8
Vulnerability from github – Published: 2024-08-19 18:32 – Updated: 2024-08-19 18:32Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Crocoblock JetGridBuilder allows PHP Local File Inclusion.This issue affects JetGridBuilder: from n/a through 1.1.2.
{
"affected": [],
"aliases": [
"CVE-2024-43221"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-08-19T17:15:08Z",
"severity": "HIGH"
},
"details": "Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027) vulnerability in Crocoblock JetGridBuilder allows PHP Local File Inclusion.This issue affects JetGridBuilder: from n/a through 1.1.2.",
"id": "GHSA-fwg4-px6f-6fj8",
"modified": "2024-08-19T18:32:08Z",
"published": "2024-08-19T18:32:08Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-43221"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/vulnerability/jetgridbuilder/wordpress-jetgridbuilder-plugin-1-1-2-local-file-inclusion-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-FWGX-G9WP-QJG6
Vulnerability from github – Published: 2022-05-24 17:33 – Updated: 2022-05-24 17:33Path traversal in the Intel(R) EMA before version 1.3.3 may allow an unauthenticated user to potentially enable escalation of privilege via network access.
{
"affected": [],
"aliases": [
"CVE-2020-12315"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-11-12T19:15:00Z",
"severity": "CRITICAL"
},
"details": "Path traversal in the Intel(R) EMA before version 1.3.3 may allow an unauthenticated user to potentially enable escalation of privilege via network access.",
"id": "GHSA-fwgx-g9wp-qjg6",
"modified": "2022-05-24T17:33:32Z",
"published": "2022-05-24T17:33:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-12315"
},
{
"type": "WEB",
"url": "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00412"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-FWH2-95JW-G4J6
Vulnerability from github – Published: 2026-06-19 00:31 – Updated: 2026-06-19 21:33Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-766v-q9x3-g744. This link is maintained to preserve external references.
Original Description
PraisonAI before 1.5.115 contains a path traversal vulnerability in MultiAgentMonitor that fails to sanitize agent IDs when building file paths. Attackers can include traversal sequences like ../ in agent IDs to read, write, or overwrite arbitrary files, enabling sensitive disclosure, denial of service, or code execution.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "praisonai"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "1.5.114"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-19T21:33:26Z",
"nvd_published_at": "2026-06-18T23:16:19Z",
"severity": "HIGH"
},
"details": "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of\u00a0GHSA-766v-q9x3-g744. This link is maintained to preserve external references.\n\n## Original Description\nPraisonAI before 1.5.115 contains a path traversal vulnerability in MultiAgentMonitor that fails to sanitize agent IDs when building file paths. Attackers can include traversal sequences like ../ in agent IDs to read, write, or overwrite arbitrary files, enabling sensitive disclosure, denial of service, or code execution.",
"id": "GHSA-fwh2-95jw-g4j6",
"modified": "2026-06-19T21:33:26Z",
"published": "2026-06-19T00:31:37Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-766v-q9x3-g744"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56078"
},
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/praisonai-arbitrary-file-read-and-write-via-path-traversal-in-multiagentmonitor"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Duplicate Advisory: PraisonAI has Memory State Leakage and Path Traversal in MultiAgent Context Handling",
"withdrawn": "2026-06-19T21:33:26Z"
}
GHSA-FWHX-4VQR-M9GJ
Vulnerability from github – Published: 2026-04-16 03:31 – Updated: 2026-04-16 03:31OpenHarness prior to commit dd1d235 contains a path traversal vulnerability that allows remote gateway users with chat access to read arbitrary files by supplying path traversal sequences to the /memory show slash command. Attackers can manipulate the path input parameter to escape the project memory directory and access sensitive files accessible to the OpenHarness process without filesystem containment validation.
{
"affected": [],
"aliases": [
"CVE-2026-40503"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-16T01:16:11Z",
"severity": "HIGH"
},
"details": "OpenHarness prior to commit dd1d235 contains a path traversal vulnerability that allows remote gateway users with chat access to read arbitrary files by supplying path traversal sequences to the /memory show slash command. Attackers can manipulate the path input parameter to escape the project memory directory and access sensitive files accessible to the OpenHarness process without filesystem containment validation.",
"id": "GHSA-fwhx-4vqr-m9gj",
"modified": "2026-04-16T03:31:06Z",
"published": "2026-04-16T03:31:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40503"
},
{
"type": "WEB",
"url": "https://github.com/HKUDS/OpenHarness/pull/127"
},
{
"type": "WEB",
"url": "https://github.com/HKUDS/OpenHarness/commit/dd1d235450dd987b20bff01b7bfb02fe8620a0af"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/openharness-path-traversal-information-disclosure-via-memory-show"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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-FWJ3-42WH-8673
Vulnerability from github – Published: 2026-05-07 03:28 – Updated: 2026-05-14 20:54Summary
Attacker-controlled path input is joined with a trusted base path prior to sanitization, allowing traversal sequences (e.g., ../) to escape the intended shared directory. As a result, an unauthenticated attacker possessing a valid public share hash with delete permissions enabled can delete arbitrary files outside the shared directory within the share owner’s configured storage scope.
Affected Components
Two distinct vulnerable code paths:
- Stable versions (e.g., gtstef/filebrowser:stable)
DELETE /public/api/resources?hash=<hash>&path=../victimRoot cause: middleware.go:111 Issue: path query parameter is joined before SanitizeUserPath() - Development / HEAD (e.g., commit eabdfd9)
DELETE /public/api/resources/bulk?hash=<hash>Body: [{"path":"../victim"}] Root cause: resource.go:274 Issue: item.Path is joined before SanitizeUserPath()
Steps to reproduce (Stable Version)
1. Create a directory structure:
/folder/shared_subdir/ (shared)
/folder/protected.txt (outside shared directory)
2. Create a public share:
Path: /shared_subdir
AllowDelete=true
3. Send request:
curl -X DELETE "http://localhost/public/api/resources?hash=<HASH>&path=../protected.txt"
#Observe:
#protected.txt is deleted despite being outside the shared directory
Proof of Concept (HEAD / bulk endpoint)
curl -X DELETE "http://localhost/public/api/resources/bulk?hash=<HASH>" \
-H "Content-Type: application/json" \
-d '[{"path":"../protected.txt"}]'
Alternative PoC Scripts:
poc_v3.sh (If the script fails due to environment differences, the manual PoC above reliably reproduces the issue.)
Impact
An unauthenticated attacker with access to a public share link configured with delete permissions enabled can delete attacker-chosen files outside the shared directory, anywhere within the share owner’s storage scope. This results in unauthorized data loss and potential service disruption.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/gtsteffaniak/filebrowser"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260501183844-112740bdd41d"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-44542"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-07T03:28:06Z",
"nvd_published_at": "2026-05-14T18:16:50Z",
"severity": "CRITICAL"
},
"details": "### **Summary**\n\nAttacker-controlled path input is joined with a trusted base path prior to sanitization, allowing traversal sequences (e.g., ../) to escape the intended shared directory. As a result, an unauthenticated attacker possessing a valid public share hash with delete permissions enabled can delete arbitrary files outside the shared directory within the share owner\u2019s configured storage scope.\n\n### **Affected Components**\n\n**Two distinct vulnerable code paths:**\n\n1. Stable versions (e.g., gtstef/filebrowser:stable)\n`DELETE /public/api/resources?hash=\u003chash\u003e\u0026path=../victim`\nRoot cause: middleware.go:111\nIssue: path query parameter is joined before SanitizeUserPath()\n2. Development / HEAD (e.g., commit eabdfd9)\n`DELETE /public/api/resources/bulk?hash=\u003chash\u003e`\nBody: [{\"path\":\"../victim\"}]\nRoot cause: resource.go:274\nIssue: item.Path is joined before SanitizeUserPath()\n\n### **Steps to reproduce (Stable Version)**\n\n**1. Create a directory structure:**\n\n```\n/folder/shared_subdir/ (shared)\n/folder/protected.txt (outside shared directory)\n```\n\n**2. Create a public share:**\n```\nPath: /shared_subdir\nAllowDelete=true\n```\n\n**3. Send request:**\n\n```\ncurl -X DELETE \"http://localhost/public/api/resources?hash=\u003cHASH\u003e\u0026path=../protected.txt\"\n\n#Observe:\n#protected.txt is deleted despite being outside the shared directory\n```\n\n### **Proof of Concept (HEAD / bulk endpoint)**\n\n```\ncurl -X DELETE \"http://localhost/public/api/resources/bulk?hash=\u003cHASH\u003e\" \\\n -H \"Content-Type: application/json\" \\\n -d \u0027[{\"path\":\"../protected.txt\"}]\u0027\n```\n\n### **Alternative PoC Scripts:**\n[poc_v3.sh](https://github.com/user-attachments/files/26159404/poc_v3.sh) (**If the script fails due to environment differences, the manual PoC above reliably reproduces the issue.**)\n\n\n### **Impact**\nAn unauthenticated attacker with access to a public share link configured with delete permissions enabled can delete attacker-chosen files outside the shared directory, anywhere within the share owner\u2019s storage scope. This results in unauthorized data loss and potential service disruption.",
"id": "GHSA-fwj3-42wh-8673",
"modified": "2026-05-14T20:54:32Z",
"published": "2026-05-07T03:28:06Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-fwj3-42wh-8673"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44542"
},
{
"type": "WEB",
"url": "https://github.com/gtsteffaniak/filebrowser/commit/112740bdd41de7d5eb01e13ba49d406bfc463f69"
},
{
"type": "PACKAGE",
"url": "https://github.com/gtsteffaniak/filebrowser"
}
],
"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:H",
"type": "CVSS_V3"
}
],
"summary": "FileBrowser Public Share DELETE API Path Traversal Allows Unauthenticated Arbitrary File Deletion"
}
GHSA-FWJ7-298V-7488
Vulnerability from github – Published: 2024-09-13 18:31 – Updated: 2024-09-13 18:31A vulnerability was found in JFinalCMS up to 1.0. It has been rated as critical. This issue affects the function delete of the file /admin/template/edit. The manipulation of the argument name leads to path traversal. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.
{
"affected": [],
"aliases": [
"CVE-2024-8782"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-13T18:15:07Z",
"severity": "MODERATE"
},
"details": "A vulnerability was found in JFinalCMS up to 1.0. It has been rated as critical. This issue affects the function delete of the file /admin/template/edit. The manipulation of the argument name leads to path traversal. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.",
"id": "GHSA-fwj7-298v-7488",
"modified": "2024-09-13T18:31:48Z",
"published": "2024-09-13T18:31:48Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-8782"
},
{
"type": "WEB",
"url": "https://gitee.com/heyewei/JFinalcms/issues/IAOSJG"
},
{
"type": "WEB",
"url": "https://github.com/yhy7612/Seccode/blob/main/README1.md"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.277433"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.277433"
},
{
"type": "WEB",
"url": "https://vuldb.com/?submit.405528"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/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-FWJ8-64XX-FWH9
Vulnerability from github – Published: 2022-11-07 12:00 – Updated: 2022-11-10 12:01The Import any XML or CSV File to WordPress plugin before 3.6.9 is not validating the paths of files contained in uploaded zip archives, allowing highly privileged users, such as admins, to write arbitrary files to any part of the file system accessible by the web server via a path traversal vector.
{
"affected": [],
"aliases": [
"CVE-2022-2711"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-11-07T10:15:00Z",
"severity": "HIGH"
},
"details": "The Import any XML or CSV File to WordPress plugin before 3.6.9 is not validating the paths of files contained in uploaded zip archives, allowing highly privileged users, such as admins, to write arbitrary files to any part of the file system accessible by the web server via a path traversal vector.",
"id": "GHSA-fwj8-64xx-fwh9",
"modified": "2022-11-10T12:01:17Z",
"published": "2022-11-07T12:00:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-2711"
},
{
"type": "WEB",
"url": "https://wpscan.com/vulnerability/11e73c23-ff5f-42e5-a4b0-0971652dcea1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-FWR5-W9HQ-MX49
Vulnerability from github – Published: 2024-11-22 21:32 – Updated: 2024-11-22 21:32Allegra unzipFile Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Allegra. Authentication is required to exploit this vulnerability.
The specific flaw exists within the unzipFile method. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of LOCAL SERVICE. Was ZDI-CAN-23453.
{
"affected": [],
"aliases": [
"CVE-2024-5581"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-11-22T20:15:09Z",
"severity": "HIGH"
},
"details": "Allegra unzipFile Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Allegra. Authentication is required to exploit this vulnerability.\n\nThe specific flaw exists within the unzipFile method. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of LOCAL SERVICE. Was ZDI-CAN-23453.",
"id": "GHSA-fwr5-w9hq-mx49",
"modified": "2024-11-22T21:32:16Z",
"published": "2024-11-22T21:32:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-5581"
},
{
"type": "WEB",
"url": "https://alltena.com/en/resources/release-notes/relnotes-7-5-2"
},
{
"type": "WEB",
"url": "https://www.zerodayinitiative.com/advisories/ZDI-24-1164"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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.