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.
13346 vulnerabilities reference this CWE, most recent first.
GHSA-JCQ4-G9PC-2RR8
Vulnerability from github – Published: 2022-05-17 00:42 – Updated: 2022-05-17 00:42Directory traversal vulnerability in webcamXP 5.3.2.375 and 5.3.2.410 build 2132 allows remote attackers to read arbitrary files via a ..%2F (encoded dot dot slash) in the URI.
{
"affected": [],
"aliases": [
"CVE-2008-5862"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2009-01-06T17:30:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in webcamXP 5.3.2.375 and 5.3.2.410 build 2132 allows remote attackers to read arbitrary files via a ..%2F (encoded dot dot slash) in the URI.",
"id": "GHSA-jcq4-g9pc-2rr8",
"modified": "2022-05-17T00:42:31Z",
"published": "2022-05-17T00:42:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-5862"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/47492"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/7521"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/33257"
},
{
"type": "WEB",
"url": "http://securityreason.com/securityalert/4877"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/32928"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id?1021484"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-JCQ6-J25V-GR6G
Vulnerability from github – Published: 2022-03-24 00:00 – Updated: 2022-03-30 00:01Rockwell Automation Connected Components Workbench v12.00.00 and prior does not sanitize paths specified within the .ccwarc archive file during extraction. This type of vulnerability is also commonly referred to as a Zip Slip. A local, authenticated attacker can create a malicious .ccwarc archive file that, when opened by Connected Components Workbench, will allow the attacker to gain the privileges of the software. If the software is running at SYSTEM level, the attacker will gain admin level privileges. User interaction is required for this exploit to be successful.
{
"affected": [],
"aliases": [
"CVE-2021-27473"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-03-23T20:15:00Z",
"severity": "HIGH"
},
"details": "Rockwell Automation Connected Components Workbench v12.00.00 and prior does not sanitize paths specified within the .ccwarc archive file during extraction. This type of vulnerability is also commonly referred to as a Zip Slip. A local, authenticated attacker can create a malicious .ccwarc archive file that, when opened by Connected Components Workbench, will allow the attacker to gain the privileges of the software. If the software is running at SYSTEM level, the attacker will gain admin level privileges. User interaction is required for this exploit to be successful.",
"id": "GHSA-jcq6-j25v-gr6g",
"modified": "2022-03-30T00:01:02Z",
"published": "2022-03-24T00:00:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-27473"
},
{
"type": "WEB",
"url": "https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1131435"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/uscert/ics/advisories/icsa-21-133-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-JCQP-84R8-2Q6F
Vulnerability from github – Published: 2024-09-26 15:30 – Updated: 2024-09-26 18:31An issue in the Http_handle object of VONETS VAP11G-300 v3.3.23.6.9 allows attackers to access sensitive files via a directory traversal.
{
"affected": [],
"aliases": [
"CVE-2024-46327"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-26T14:15:09Z",
"severity": "MODERATE"
},
"details": "An issue in the Http_handle object of VONETS VAP11G-300 v3.3.23.6.9 allows attackers to access sensitive files via a directory traversal.",
"id": "GHSA-jcqp-84r8-2q6f",
"modified": "2024-09-26T18:31:44Z",
"published": "2024-09-26T15:30:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-46327"
},
{
"type": "WEB",
"url": "https://hawktesters.com/5519644d-246e-4924-b7c8-8fdf742117be/ab3b22c9-1fbf-4dbb-a1cd-8c69f6723a4a.pdf"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-JCRP-X7W3-FFMG
Vulnerability from github – Published: 2025-01-29 22:21 – Updated: 2025-10-14 21:54Summary
Deep Java Library (DJL) is an open-source, high-level, engine-agnostic Java framework for deep learning. DJL is designed to be easy to get started with and simple to use for Java developers. DJL provides a native Java development experience and functions like any other regular Java library.
DJL provides utilities for extracting tar and zip model archives that are used when loading models for use with DJL. These utilities were found to contain issues that do not protect against absolute path traversal during the extraction process.
Impact
An issue exists with DJL's untar and unzip functionalities. Specifically, it is possible to create an archive on a Windows system, and when extracted on a MacOS or Linux system, write artifacts outside the intended destination during the extraction process. The reverse is also true for archives created on MacOS/Linux systems and extracted on Windows systems.
Impacted versions: 0.1.0 - 0.31.0
Patches
This issue has been patched in DJL 0.31.1 [1]
Workarounds
Do not use model archive files from sources you do not trust. You should only use model archives from official sources like the DJL Model Zoo, or models that you have created and packaged yourself.
References
If you have any questions or comments about this advisory, we ask that you contact AWS/Amazon Security via our vulnerability reporting page [2] or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
[1] https://github.com/deepjavalibrary/djl/tree/v0.31.1 [2] https://aws.amazon.com/security/vulnerability-reporting
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "ai.djl:api"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.31.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-0851"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-36"
],
"github_reviewed": true,
"github_reviewed_at": "2025-01-29T22:21:33Z",
"nvd_published_at": "2025-01-29T22:15:30Z",
"severity": "CRITICAL"
},
"details": "## Summary\n\n[Deep Java Library (DJL)](https://docs.djl.ai/master/index.html) is an open-source, high-level, engine-agnostic Java framework for deep learning. DJL is designed to be easy to get started with and simple to use for Java developers. DJL provides a native Java development experience and functions like any other regular Java library.\n\nDJL provides utilities for extracting tar and zip model archives that are used when loading models for use with DJL. These utilities were found to contain issues that do not protect against absolute path traversal during the extraction process.\n\n## Impact\n\nAn issue exists with DJL\u0027s untar and unzip functionalities. Specifically, it is possible to create an archive on a Windows system, and when extracted on a MacOS or Linux system, write artifacts outside the intended destination during the extraction process. The reverse is also true for archives created on MacOS/Linux systems and extracted on Windows systems.\n\nImpacted versions: 0.1.0 - 0.31.0\n\n## Patches\n\nThis issue has been patched in DJL 0.31.1 [1]\n\n## Workarounds\n\nDo not use model archive files from sources you do not trust. You should only use model archives from official sources like the DJL Model Zoo, or models that you have created and packaged yourself.\n\n## References\n\nIf you have any questions or comments about this advisory, we ask that you contact AWS/Amazon Security via our vulnerability reporting page [2] or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.\n\n[1] https://github.com/deepjavalibrary/djl/tree/v0.31.1\n[2] https://aws.amazon.com/security/vulnerability-reporting",
"id": "GHSA-jcrp-x7w3-ffmg",
"modified": "2025-10-14T21:54:30Z",
"published": "2025-01-29T22:21:33Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/deepjavalibrary/djl/security/advisories/GHSA-jcrp-x7w3-ffmg"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-0851"
},
{
"type": "WEB",
"url": "https://github.com/deepjavalibrary/djl/commit/7415cc5f72aae69ea9716a5e4f709af03a77a619"
},
{
"type": "WEB",
"url": "https://aws.amazon.com/security/security-bulletins/AWS-2025-003"
},
{
"type": "PACKAGE",
"url": "https://github.com/deepjavalibrary/djl"
},
{
"type": "WEB",
"url": "https://github.com/deepjavalibrary/djl/releases/tag/v0.31.1"
}
],
"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"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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"
}
],
"summary": "Deep Java Library path traversal issue"
}
GHSA-JCVF-2RHC-M6H8
Vulnerability from github – Published: 2022-05-14 01:13 – Updated: 2022-05-14 01:13** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application.
{
"affected": [],
"aliases": [
"CVE-2018-18586"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-10-23T02:29:00Z",
"severity": "MODERATE"
},
"details": "** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application.",
"id": "GHSA-jcvf-2rhc-m6h8",
"modified": "2022-05-14T01:13:39Z",
"published": "2022-05-14T01:13:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-18586"
},
{
"type": "WEB",
"url": "https://github.com/kyz/libmspack/commit/7cadd489698be117c47efcadd742651594429e6d"
},
{
"type": "WEB",
"url": "https://bugs.debian.org/911639"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/201903-20"
},
{
"type": "WEB",
"url": "https://www.openwall.com/lists/oss-security/2018/10/22/1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-JCWR-VR95-X32M
Vulnerability from github – Published: 2023-02-24 12:31 – Updated: 2023-03-06 18:30A vulnerability classified as problematic has been found in DrayTek Vigor 2960 1.5.1.4. Affected is the function sub_1DF14 of the file /cgi-bin/mainfunction.cgi. The manipulation of the argument option with the input /../etc/password leads to path traversal. The attack needs to be done within the local network. The exploit has been disclosed to the public and may be used. VDB-221742 is the identifier assigned to this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2023-1009"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-02-24T11:15:00Z",
"severity": "MODERATE"
},
"details": "A vulnerability classified as problematic has been found in DrayTek Vigor 2960 1.5.1.4. Affected is the function sub_1DF14 of the file /cgi-bin/mainfunction.cgi. The manipulation of the argument option with the input /../etc/password leads to path traversal. The attack needs to be done within the local network. The exploit has been disclosed to the public and may be used. VDB-221742 is the identifier assigned to this vulnerability.",
"id": "GHSA-jcwr-vr95-x32m",
"modified": "2023-03-06T18:30:20Z",
"published": "2023-02-24T12:31:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-1009"
},
{
"type": "WEB",
"url": "https://github.com/xxy1126/Vuln/blob/main/Draytek/1.md"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.221742"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.221742"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-JCX7-MQQF-7JXJ
Vulnerability from github – Published: 2022-05-24 17:24 – Updated: 2022-05-24 17:24Dell EMC OpenManage Server Administrator (OMSA) versions 9.4 and prior contain multiple path traversal vulnerabilities. An unauthenticated remote attacker could potentially exploit these vulnerabilities by sending a crafted Web API request containing directory traversal character sequences to gain file system access on the compromised management station.
{
"affected": [],
"aliases": [
"CVE-2020-5377"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-07-28T18:15:00Z",
"severity": "MODERATE"
},
"details": "Dell EMC OpenManage Server Administrator (OMSA) versions 9.4 and prior contain multiple path traversal vulnerabilities. An unauthenticated remote attacker could potentially exploit these vulnerabilities by sending a crafted Web API request containing directory traversal character sequences to gain file system access on the compromised management station.",
"id": "GHSA-jcx7-mqqf-7jxj",
"modified": "2022-05-24T17:24:34Z",
"published": "2022-05-24T17:24:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-5377"
},
{
"type": "WEB",
"url": "https://www.dell.com/support/article/en-us/sln322304/dsa-2020-172-dell-emc-openmanage-server-administrator-omsa-path-traversal-vulnerability?lang=en"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/162110/Dell-OpenManage-Server-Administrator-9.4.0.0-File-Read.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-JCXV-6F65-7HRX
Vulnerability from github – Published: 2022-05-24 19:01 – Updated: 2025-10-22 00:32Microsoft Exchange Server Security Feature Bypass Vulnerability
{
"affected": [],
"aliases": [
"CVE-2021-31207"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-434"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-05-11T19:15:00Z",
"severity": "HIGH"
},
"details": "Microsoft Exchange Server Security Feature Bypass Vulnerability",
"id": "GHSA-jcxv-6f65-7hrx",
"modified": "2025-10-22T00:32:13Z",
"published": "2022-05-24T19:01:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-31207"
},
{
"type": "WEB",
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31207"
},
{
"type": "WEB",
"url": "https://www.zerodayinitiative.com/advisories/ZDI-21-819"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html"
}
],
"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-JF25-7968-H2H5
Vulnerability from github – Published: 2026-04-17 21:58 – Updated: 2026-05-05 11:59Summary
screen_record outPath bypassed workspace-only filesystem guard.
Affected Packages / Versions
- Package:
openclaw - Ecosystem: npm
- Affected versions:
< 2026.4.10 - Patched versions:
>= 2026.4.10
Impact
The node-host screen recording tool could honor an outPath outside the workspace guard, allowing an authorized tool call to write outside the intended workspace boundary.
Technical Details
The fix applies the workspace-root guard to node tool outPath handling, including screen recording paths.
Fix
The issue was fixed in #63551. The first stable tag containing the fix is v2026.4.10, and openclaw@2026.4.14 includes the fix.
Fix Commit(s)
635bb35b68d8faa5bfa2fda35feadd315122748a- PR: #63551
Release Process Note
Users should upgrade to openclaw 2026.4.10 or newer. The latest npm release, 2026.4.14, already includes the fix.
Credits
Thanks to @anshumanbh for reporting this issue.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "openclaw"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.4.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-43567"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-17T21:58:24Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "## Summary\n\nscreen_record outPath bypassed workspace-only filesystem guard.\n\n## Affected Packages / Versions\n\n- Package: `openclaw`\n- Ecosystem: npm\n- Affected versions: `\u003c 2026.4.10`\n- Patched versions: `\u003e= 2026.4.10`\n\n## Impact\n\nThe node-host screen recording tool could honor an `outPath` outside the workspace guard, allowing an authorized tool call to write outside the intended workspace boundary.\n\n## Technical Details\n\nThe fix applies the workspace-root guard to node tool `outPath` handling, including screen recording paths.\n\n## Fix\n\nThe issue was fixed in #63551. The first stable tag containing the fix is `v2026.4.10`, and `openclaw@2026.4.14` includes the fix.\n\n## Fix Commit(s)\n\n- `635bb35b68d8faa5bfa2fda35feadd315122748a`\n- PR: #63551\n\n## Release Process Note\n\nUsers should upgrade to `openclaw` 2026.4.10 or newer. The latest npm release, `2026.4.14`, already includes the fix.\n\n## Credits\n\nThanks to @anshumanbh for reporting this issue.",
"id": "GHSA-jf25-7968-h2h5",
"modified": "2026-05-05T11:59:48Z",
"published": "2026-04-17T21:58:24Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-jf25-7968-h2h5"
},
{
"type": "WEB",
"url": "https://github.com/openclaw/openclaw/pull/63551"
},
{
"type": "WEB",
"url": "https://github.com/openclaw/openclaw/commit/635bb35b68d8faa5bfa2fda35feadd315122748a"
},
{
"type": "PACKAGE",
"url": "https://github.com/openclaw/openclaw"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "OpenClaw: screen_record outPath bypassed workspace-only filesystem guard"
}
GHSA-JF2J-R53V-M3V2
Vulnerability from github – Published: 2024-05-03 03:30 – Updated: 2025-08-13 12:31Pulse Secure Client SetupService Directory Traversal Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Pulse Secure Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within SetupService. 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 escalate privileges and execute arbitrary code in the context of the service. Was ZDI-CAN-17687.
{
"affected": [],
"aliases": [
"CVE-2023-34298"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-03T02:15:30Z",
"severity": "HIGH"
},
"details": "Pulse Secure Client SetupService Directory Traversal Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Pulse Secure Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.\n\nThe specific flaw exists within SetupService. 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 escalate privileges and execute arbitrary code in the context of the service. Was ZDI-CAN-17687.",
"id": "GHSA-jf2j-r53v-m3v2",
"modified": "2025-08-13T12:31:29Z",
"published": "2024-05-03T03:30:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-34298"
},
{
"type": "WEB",
"url": "https://forums.ivanti.com/s/article/CVE-2023-34298-Ivanti-Secure-Access-Client-local-privilege-escalation?language=en_US"
},
{
"type": "WEB",
"url": "https://www.zerodayinitiative.com/advisories/ZDI-23-858"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/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.