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.
13025 vulnerabilities reference this CWE, most recent first.
GHSA-3W6H-PP32-QHJ8
Vulnerability from github – Published: 2022-05-13 01:31 – Updated: 2022-05-13 01:31Directory Traversal vulnerability in McAfee ePolicy Orchestrator (ePO) 5.3.2, 5.3.1, 5.3.0 and 5.9.0 allows administrators to use Windows alternate data streams, which could be used to bypass the file extensions, via not properly validating the path when exporting a particular XML file.
{
"affected": [],
"aliases": [
"CVE-2018-6660"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-04-02T13:29:00Z",
"severity": "MODERATE"
},
"details": "Directory Traversal vulnerability in McAfee ePolicy Orchestrator (ePO) 5.3.2, 5.3.1, 5.3.0 and 5.9.0 allows administrators to use Windows alternate data streams, which could be used to bypass the file extensions, via not properly validating the path when exporting a particular XML file.",
"id": "GHSA-3w6h-pp32-qhj8",
"modified": "2022-05-13T01:31:59Z",
"published": "2022-05-13T01:31:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-6660"
},
{
"type": "WEB",
"url": "https://kc.mcafee.com/corporate/index?page=content\u0026id=SB10228"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/103392"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1040884"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3W6M-X2X7-982W
Vulnerability from github – Published: 2022-05-01 23:58 – Updated: 2022-05-01 23:58Directory traversal vulnerability in modules/system/admin.php in XOOPS 2.0.18 1 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the fct parameter. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
{
"affected": [],
"aliases": [
"CVE-2008-3296"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-07-25T13:41:00Z",
"severity": "HIGH"
},
"details": "Directory traversal vulnerability in modules/system/admin.php in XOOPS 2.0.18 1 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the fct parameter. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.",
"id": "GHSA-3w6m-x2x7-982w",
"modified": "2022-05-01T23:58:44Z",
"published": "2022-05-01T23:58:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-3296"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/43966"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/30330"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3W6X-7R98-7Q22
Vulnerability from github – Published: 2026-03-05 06:30 – Updated: 2026-03-09 18:31Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in wpWax FormGent formgent allows Path Traversal.This issue affects FormGent: from n/a through <= 1.4.2.
{
"affected": [],
"aliases": [
"CVE-2026-22460"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-05T06:16:20Z",
"severity": "HIGH"
},
"details": "Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027) vulnerability in wpWax FormGent formgent allows Path Traversal.This issue affects FormGent: from n/a through \u003c= 1.4.2.",
"id": "GHSA-3w6x-7r98-7q22",
"modified": "2026-03-09T18:31:37Z",
"published": "2026-03-05T06:30:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-22460"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Plugin/formgent/vulnerability/wordpress-formgent-plugin-1-2-1-arbitrary-file-deletion-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-3W7P-GC55-64XR
Vulnerability from github – Published: 2022-05-13 01:35 – Updated: 2022-05-13 01:35A Path Traversal vulnerability in the diagnostic shell for Cisco IOS and IOS XE Software could allow an authenticated, local attacker to use certain diagnostic shell commands that can overwrite system files. These system files may be sensitive and should not be able to be overwritten by a user of the diagnostic shell. The vulnerability is due to lack of proper input validation for certain diagnostic shell commands. An attacker could exploit this vulnerability by authenticating to the device, entering the diagnostic shell, and providing crafted user input to commands at the local diagnostic shell CLI. Successful exploitation could allow the attacker to overwrite system files that should be restricted. Cisco Bug IDs: CSCvg41950.
{
"affected": [],
"aliases": [
"CVE-2018-0123"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-02-08T07:29:00Z",
"severity": "MODERATE"
},
"details": "A Path Traversal vulnerability in the diagnostic shell for Cisco IOS and IOS XE Software could allow an authenticated, local attacker to use certain diagnostic shell commands that can overwrite system files. These system files may be sensitive and should not be able to be overwritten by a user of the diagnostic shell. The vulnerability is due to lack of proper input validation for certain diagnostic shell commands. An attacker could exploit this vulnerability by authenticating to the device, entering the diagnostic shell, and providing crafted user input to commands at the local diagnostic shell CLI. Successful exploitation could allow the attacker to overwrite system files that should be restricted. Cisco Bug IDs: CSCvg41950.",
"id": "GHSA-3w7p-gc55-64xr",
"modified": "2022-05-13T01:35:46Z",
"published": "2022-05-13T01:35:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-0123"
},
{
"type": "WEB",
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180207-ios"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/102967"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1040346"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3W7X-45WJ-HGJM
Vulnerability from github – Published: 2022-05-17 05:34 – Updated: 2022-05-17 05:34Directory traversal vulnerability in index.php in OneOrZero AIMS 2.6.0 Members Edition allows remote authenticated users to read arbitrary files via directory traversal sequences in the controller parameter in a show_report action.
{
"affected": [],
"aliases": [
"CVE-2010-4835"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2011-09-14T02:56:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in index.php in OneOrZero AIMS 2.6.0 Members Edition allows remote authenticated users to read arbitrary files via directory traversal sequences in the controller parameter in a show_report action.",
"id": "GHSA-3w7x-45wj-hgjm",
"modified": "2022-05-17T05:34:15Z",
"published": "2022-05-17T05:34:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2010-4835"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.org/files/view/95814/oneorzeroaims-lfisql.txt"
},
{
"type": "WEB",
"url": "http://securityreason.com/securityalert/8375"
},
{
"type": "WEB",
"url": "http://www.exploit-db.com/exploits/15519"
},
{
"type": "WEB",
"url": "http://www.xenuser.org/documents/security/OneOrZero_Aims_multiple_vulnerabilities.txt"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3W8X-76PC-54FP
Vulnerability from github – Published: 2022-05-14 03:49 – Updated: 2022-05-14 03:49The GD Rating System plugin 2.3 for WordPress has Directory Traversal in the wp-admin/admin.php panel parameter for the gd-rating-system-information page.
{
"affected": [],
"aliases": [
"CVE-2018-5289"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-01-08T07:29:00Z",
"severity": "HIGH"
},
"details": "The GD Rating System plugin 2.3 for WordPress has Directory Traversal in the wp-admin/admin.php panel parameter for the gd-rating-system-information page.",
"id": "GHSA-3w8x-76pc-54fp",
"modified": "2022-05-14T03:49:05Z",
"published": "2022-05-14T03:49:05Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-5289"
},
{
"type": "WEB",
"url": "https://github.com/d4wner/Vulnerabilities-Report/blob/master/gd-rating-system.md"
},
{
"type": "WEB",
"url": "https://wordpress.org/support/topic/xss-lfi-bugs-at-the-latest-version-of-gd-rating-system"
},
{
"type": "WEB",
"url": "https://wpvulndb.com/vulnerabilities/8995"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3W97-9V6V-7C57
Vulnerability from github – Published: 2022-08-06 00:00 – Updated: 2022-08-12 00:01** UNSUPPORTED WHEN ASSIGNED ** A vulnerability in Brocade Fabric OS versions v7.4.1b and v7.3.1d could allow local users to conduct privileged directory transversal. Brocade Fabric OS versions v7.4.1.x and v7.3.x have reached end of life. Brocade Fabric OS Users should upgrade to supported versions as described in the Product End-of-Life Publish report.
{
"affected": [],
"aliases": [
"CVE-2021-27798"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-08-05T16:15:00Z",
"severity": "MODERATE"
},
"details": "** UNSUPPORTED WHEN ASSIGNED ** A vulnerability in Brocade Fabric OS versions v7.4.1b and v7.3.1d could allow local users to conduct privileged directory transversal. Brocade Fabric OS versions v7.4.1.x and v7.3.x have reached end of life. Brocade Fabric OS Users should upgrade to supported versions as described in the Product End-of-Life Publish report.",
"id": "GHSA-3w97-9v6v-7c57",
"modified": "2022-08-12T00:01:24Z",
"published": "2022-08-06T00:00:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-27798"
},
{
"type": "WEB",
"url": "https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2022-2012"
}
],
"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-3WC8-MXPJ-88PJ
Vulnerability from github – Published: 2022-05-02 00:01 – Updated: 2022-05-02 00:01Directory traversal vulnerability in index.php in SyzygyCMS 0.3 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the page parameter.
{
"affected": [],
"aliases": [
"CVE-2008-3593"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-08-11T23:41:00Z",
"severity": "HIGH"
},
"details": "Directory traversal vulnerability in index.php in SyzygyCMS 0.3 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the page parameter.",
"id": "GHSA-3wc8-mxpj-88pj",
"modified": "2022-05-02T00:01:43Z",
"published": "2022-05-02T00:01:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-3593"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/44157"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/6200"
},
{
"type": "WEB",
"url": "http://securityreason.com/securityalert/4138"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/30530"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3WF8-VWMJ-P686
Vulnerability from github – Published: 2026-03-21 00:31 – Updated: 2026-03-21 00:31The EmailKit – Email Customizer for WooCommerce & WP plugin for WordPress is vulnerable to arbitrary file read via path traversal in all versions up to, and including, 1.6.3. This is due to the action() function in the TemplateData class passing user-supplied input from the 'emailkit-editor-template' REST API parameter directly to file_get_contents() without any path validation, sanitization, or restriction to an allowed directory. This makes it possible for authenticated attackers, with Administrator-level access, to read arbitrary files on the server (such as /etc/passwd or wp-config.php) by supplying a traversal path. The file contents are stored as post meta and can subsequently be retrieved via the fetch-data REST API endpoint. Notably, the CheckForm class in the same plugin implements proper path validation using realpath() and directory restriction, demonstrating that the developer was aware of the risk but failed to apply the same protections to the TemplateData endpoint.
{
"affected": [],
"aliases": [
"CVE-2026-3474"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-21T00:16:28Z",
"severity": "MODERATE"
},
"details": "The EmailKit \u2013 Email Customizer for WooCommerce \u0026 WP plugin for WordPress is vulnerable to arbitrary file read via path traversal in all versions up to, and including, 1.6.3. This is due to the action() function in the TemplateData class passing user-supplied input from the \u0027emailkit-editor-template\u0027 REST API parameter directly to file_get_contents() without any path validation, sanitization, or restriction to an allowed directory. This makes it possible for authenticated attackers, with Administrator-level access, to read arbitrary files on the server (such as /etc/passwd or wp-config.php) by supplying a traversal path. The file contents are stored as post meta and can subsequently be retrieved via the fetch-data REST API endpoint. Notably, the CheckForm class in the same plugin implements proper path validation using realpath() and directory restriction, demonstrating that the developer was aware of the risk but failed to apply the same protections to the TemplateData endpoint.",
"id": "GHSA-3wf8-vwmj-p686",
"modified": "2026-03-21T00:31:44Z",
"published": "2026-03-21T00:31:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3474"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/tags/1.6.2/includes/Admin/Api/TemplateData.php#L48"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/tags/1.6.2/includes/Admin/Api/TemplateData.php#L49"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/tags/1.6.2/includes/Admin/Api/TemplateData.php#L50"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/trunk/includes/Admin/Api/TemplateData.php#L48"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/trunk/includes/Admin/Api/TemplateData.php#L49"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/emailkit/trunk/includes/Admin/Api/TemplateData.php#L50"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/changeset?sfp_email=\u0026sfph_mail=\u0026reponame=\u0026old=3484455%40emailkit\u0026new=3484455%40emailkit\u0026sfp_email=\u0026sfph_mail="
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/d8c11ebc-5c83-46a2-a8dd-b838cd50ddc6?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3WGQ-WRWC-VQMV
Vulnerability from github – Published: 2025-09-23 17:45 – Updated: 2025-11-18 16:40Impact
In versions 0.5.3 and earlier of astral-tokio-tar, tar archives may extract outside of their intended destination directory when using the Entry::unpack_in_raw API. Additionally, the Entry::allow_external_symlinks control (which defaults to true) could be bypassed via a pair of symlinks that individually point within the destination but combine to point outside of it.
These behaviors could be used individually or combined to bypass the intended security control of limiting extraction to the given directory. This in turn would allow an attacker with a malicious tar archive to perform an arbitrary file write and potentially pivot into code execution (e.g. by overwriting a file that the user or system then executes or uses to execute code).
The impact of this vulnerability for downstream API users of this crate is high, per above. However, for this crate's main downstream user (uv), the impact of this vulnerability is low due to its overlap with equivalent user capabilities in source distributions. See GHSA-7j9j-68r2-f35q for additional details.
Patches
Versions 0.5.4 and newer of astral-tokio-tar address the vulnerability above. Users should upgrade to 0.5.4 or newer.
Workarounds
Users are advised to upgrade to version 0.5.4 or newer to address this advisory.
There is no workaround other than upgrading.
References
- See GHSA-7j9j-68r2-f35q for how this vulnerability affects uv, astral-tokio-tar's primary downstream user. Observe that unlike this advisory, uv's advisory is considered low severity due to overlap with intentional existing capabilities in source distributions.
- This vulnerability is similar to (but not related in code) to CVE-2025-4138 and CVE-2025-4517, which concern Python's tarfile module.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.5.3"
},
"package": {
"ecosystem": "crates.io",
"name": "astral-tokio-tar"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.5.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-59825"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-61"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-23T17:45:07Z",
"nvd_published_at": "2025-09-23T20:15:33Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nIn versions 0.5.3 and earlier of astral-tokio-tar, tar archives may extract outside of their intended destination directory when using the `Entry::unpack_in_raw` API. Additionally, the `Entry::allow_external_symlinks` control (which defaults to `true`) could be bypassed via a pair of symlinks that individually point within the destination but combine to point outside of it.\n\nThese behaviors could be used individually or combined to bypass the intended security control of limiting extraction to the given directory. This in turn would allow an attacker with a malicious tar archive to perform an arbitrary file write and potentially pivot into code execution (e.g. by overwriting a file that the user or system then executes or uses to execute code). \n\nThe impact of this vulnerability for downstream API users of this crate is **high**, per above. However, for this crate\u0027s main downstream user (uv), the impact of this vulnerability is **low** due to its overlap with equivalent user capabilities in source distributions. See GHSA-7j9j-68r2-f35q for additional details.\n\n### Patches\n\nVersions 0.5.4 and newer of astral-tokio-tar address the vulnerability above. Users should upgrade to 0.5.4 or newer.\n\n### Workarounds\n\nUsers are advised to upgrade to version 0.5.4 or newer to address this advisory.\n\nThere is no workaround other than upgrading.\n\n### References\n\n* See GHSA-7j9j-68r2-f35q for how this vulnerability affects uv, astral-tokio-tar\u0027s primary downstream user. Observe that **unlike** this advisory, uv\u0027s advisory is considered **low severity** due to overlap with intentional existing capabilities in source distributions.\n* This vulnerability is similar to (but not related in code) to CVE-2025-4138 and CVE-2025-4517, which concern Python\u0027s tarfile module.",
"id": "GHSA-3wgq-wrwc-vqmv",
"modified": "2025-11-18T16:40:30Z",
"published": "2025-09-23T17:45:07Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/astral-sh/tokio-tar/security/advisories/GHSA-3wgq-wrwc-vqmv"
},
{
"type": "WEB",
"url": "https://github.com/google/security-research/security/advisories/GHSA-9p78-p5g6-gcj8"
},
{
"type": "WEB",
"url": "https://github.com/astral-sh/uv/issues/12163"
},
{
"type": "WEB",
"url": "https://github.com/astral-sh/tokio-tar/commit/036fdecc85c52458ace92dc9e02e9cef90684e75"
},
{
"type": "PACKAGE",
"url": "https://github.com/astral-sh/tokio-tar"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U",
"type": "CVSS_V4"
}
],
"summary": "astral-tokio-tar has a path traversal in tar extraction"
}
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.