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.
13239 vulnerabilities reference this CWE, most recent first.
GHSA-6W4P-96GH-FGFP
Vulnerability from github – Published: 2022-05-24 19:01 – Updated: 2022-05-24 19:01BTCPay Server through 1.0.7.0 suffers from directory traversal, which allows an attacker with admin privileges to achieve code execution. The attacker must craft a malicious plugin file with special characters to upload the file outside of the restricted directory.
{
"affected": [],
"aliases": [
"CVE-2021-29246"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-05-05T13:15:00Z",
"severity": "MODERATE"
},
"details": "BTCPay Server through 1.0.7.0 suffers from directory traversal, which allows an attacker with admin privileges to achieve code execution. The attacker must craft a malicious plugin file with special characters to upload the file outside of the restricted directory.",
"id": "GHSA-6w4p-96gh-fgfp",
"modified": "2022-05-24T19:01:24Z",
"published": "2022-05-24T19:01:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29246"
},
{
"type": "WEB",
"url": "https://blog.btcpayserver.org/vulnerability-disclosure-v1-0-7-0"
},
{
"type": "WEB",
"url": "https://github.com/btcpayserver/btcpayserver/releases"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6W56-HVPX-XX8J
Vulnerability from github – Published: 2022-05-24 17:18 – Updated: 2022-05-24 17:18An elevation of privilege vulnerability exists in Windows Error Reporting (WER) when WER handles and executes files, aka 'Windows Error Reporting Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1021, CVE-2020-1088.
{
"affected": [],
"aliases": [
"CVE-2020-1082"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-269"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-05-21T23:15:00Z",
"severity": "MODERATE"
},
"details": "An elevation of privilege vulnerability exists in Windows Error Reporting (WER) when WER handles and executes files, aka \u0027Windows Error Reporting Elevation of Privilege Vulnerability\u0027. This CVE ID is unique from CVE-2020-1021, CVE-2020-1088.",
"id": "GHSA-6w56-hvpx-xx8j",
"modified": "2022-05-24T17:18:26Z",
"published": "2022-05-24T17:18:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-1082"
},
{
"type": "WEB",
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1082"
},
{
"type": "WEB",
"url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1082"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-6W5Q-79RF-7C49
Vulnerability from github – Published: 2024-02-28 06:30 – Updated: 2025-01-21 22:37Webtrees 2.1.18 is vulnerable to Directory Traversal. By manipulating the "media_folder" parameter in the URL, an attacker (in this case, an administrator) can navigate beyond the intended directory (the 'media/' directory) to access sensitive files in other parts of the application's file system.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "fisharebest/webtrees"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.1.18"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-22723"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-31"
],
"github_reviewed": true,
"github_reviewed_at": "2024-08-02T16:04:10Z",
"nvd_published_at": "2024-02-28T06:15:49Z",
"severity": "MODERATE"
},
"details": "Webtrees 2.1.18 is vulnerable to Directory Traversal. By manipulating the \"media_folder\" parameter in the URL, an attacker (in this case, an administrator) can navigate beyond the intended directory (the \u0027media/\u0027 directory) to access sensitive files in other parts of the application\u0027s file system.",
"id": "GHSA-6w5q-79rf-7c49",
"modified": "2025-01-21T22:37:20Z",
"published": "2024-02-28T06:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-22723"
},
{
"type": "WEB",
"url": "https://cupc4k3.medium.com/cve-2024-22723-webtrees-vulnerability-uncovering-sensitive-data-through-path-traversal-7442e7a38b68"
},
{
"type": "PACKAGE",
"url": "https://github.com/fisharebest/webtrees"
}
],
"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"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Webtrees Path Traversal vulnerability"
}
GHSA-6W83-22GJ-5PV9
Vulnerability from github – Published: 2018-07-27 14:06 – Updated: 2023-09-11 23:13Affected versions of cyber-js resolve relative file paths, resulting in a directory traversal vulnerability. A malicious actor can use this vulnerability to access files outside of the intended directory root, which may result in the disclosure of private files on the vulnerable system.
Example request:
GET /../../../../../../../../../../etc/passwd HTTP/1.1
host:foo
Recommendation
No patch is available for this vulnerability.
It is recommended that the package is only used for local development, and if the functionality is needed for production, a different package is used instead.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "cyber-js"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "1.0.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2017-16093"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2020-06-16T21:20:22Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "Affected versions of `cyber-js` resolve relative file paths, resulting in a directory traversal vulnerability. A malicious actor can use this vulnerability to access files outside of the intended directory root, which may result in the disclosure of private files on the vulnerable system.\n\n**Example request:**\n```http\nGET /../../../../../../../../../../etc/passwd HTTP/1.1\nhost:foo\n```\n\n\n## Recommendation\n\nNo patch is available for this vulnerability.\n\nIt is recommended that the package is only used for local development, and if the functionality is needed for production, a different package is used instead.",
"id": "GHSA-6w83-22gj-5pv9",
"modified": "2023-09-11T23:13:33Z",
"published": "2018-07-27T14:06:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-16093"
},
{
"type": "WEB",
"url": "https://github.com/JacksonGL/NPM-Vuln-PoC/tree/master/directory-traversal/cyber-js"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-6w83-22gj-5pv9"
},
{
"type": "WEB",
"url": "https://www.npmjs.com/advisories/347"
}
],
"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"
}
],
"summary": "Directory Traversal in cyber-js"
}
GHSA-6W94-3R46-X632
Vulnerability from github – Published: 2022-05-24 19:12 – Updated: 2022-05-24 19:12The Zoomsounds plugin <= 6.45 for WordPress allows arbitrary files, including sensitive configuration files such as wp-config.php, to be downloaded via the dzsap_download action using directory traversal in the link parameter.
{
"affected": [],
"aliases": [
"CVE-2021-39316"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-08-31T12:15:00Z",
"severity": "HIGH"
},
"details": "The Zoomsounds plugin \u003c= 6.45 for WordPress allows arbitrary files, including sensitive configuration files such as wp-config.php, to be downloaded via the `dzsap_download` action using directory traversal in the `link` parameter.",
"id": "GHSA-6w94-3r46-x632",
"modified": "2022-05-24T19:12:37Z",
"published": "2022-05-24T19:12:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-39316"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39316"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/165146/WordPress-DZS-Zoomsounds-6.45-Arbitrary-File-Read.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6WC5-GR23-XWVQ
Vulnerability from github – Published: 2022-05-24 17:40 – Updated: 2022-05-24 17:40The Baseboard Management Controller(BMC) in HPE Cloudline CL5800 Gen9 Server; HPE Cloudline CL5200 Gen9 Server; HPE Cloudline CL4100 Gen10 Server; HPE Cloudline CL3100 Gen10 Server; HPE Cloudline CL5800 Gen10 Server BMC firmware has a local spx_restservice getvideodata_func function path traversal vulnerability.
{
"affected": [],
"aliases": [
"CVE-2021-25129"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-01-29T19:15:00Z",
"severity": "HIGH"
},
"details": "The Baseboard Management Controller(BMC) in HPE Cloudline CL5800 Gen9 Server; HPE Cloudline CL5200 Gen9 Server; HPE Cloudline CL4100 Gen10 Server; HPE Cloudline CL3100 Gen10 Server; HPE Cloudline CL5800 Gen10 Server BMC firmware has a local spx_restservice getvideodata_func function path traversal vulnerability.",
"id": "GHSA-6wc5-gr23-xwvq",
"modified": "2022-05-24T17:40:36Z",
"published": "2022-05-24T17:40:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-25129"
},
{
"type": "WEB",
"url": "https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US\u0026docId=emr_na-hpesbhf04073en_us"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6WCQ-272P-HRJW
Vulnerability from github – Published: 2025-11-08 00:31 – Updated: 2025-11-10 15:31A Local File Inclusion (LFI) vulnerability has been identified in tQuadra CMS 4.2.1117. The issue exists in the "/styles/" path, which fails to properly sanitize user-supplied input. An attacker can exploit this by sending a crafted GET request to retrieve arbitrary files from the underlying system.
{
"affected": [],
"aliases": [
"CVE-2025-60574"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-07T22:15:39Z",
"severity": "HIGH"
},
"details": "A Local File Inclusion (LFI) vulnerability has been identified in tQuadra CMS 4.2.1117. The issue exists in the \"/styles/\" path, which fails to properly sanitize user-supplied input. An attacker can exploit this by sending a crafted GET request to retrieve arbitrary files from the underlying system.",
"id": "GHSA-6wcq-272p-hrjw",
"modified": "2025-11-10T15:31:04Z",
"published": "2025-11-08T00:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-60574"
},
{
"type": "WEB",
"url": "https://github.com/jacopoaugelli/CVE-2025-60574"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6WGJ-H5FH-45P7
Vulnerability from github – Published: 2022-05-13 01:19 – Updated: 2022-05-13 01:19An issue was discovered in MetInfo 6.0.0. admin/app/batch/csvup.php allows remote attackers to delete arbitrary files via a flienamecsv=../ directory traversal. This can be exploited via CSRF.
{
"affected": [],
"aliases": [
"CVE-2018-12530"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-06-18T14:29:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in MetInfo 6.0.0. admin/app/batch/csvup.php allows remote attackers to delete arbitrary files via a flienamecsv=../ directory traversal. This can be exploited via CSRF.",
"id": "GHSA-6wgj-h5fh-45p7",
"modified": "2022-05-13T01:19:02Z",
"published": "2022-05-13T01:19:02Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-12530"
},
{
"type": "WEB",
"url": "https://github.com/summ3rf/Vulner/blob/master/Metinfo.md"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6WH5-MW9H-5C3W
Vulnerability from github – Published: 2025-10-21 18:02 – Updated: 2025-10-21 18:02Impact
Malicious actors can exploit this vulnerability to write files within arbitrary directories on the filesystem of the Shopware web container. This could allow them to gain persistent shell access by uploading a PHP-shell file to an accessible folder.
It is important to note that this vulnerability is only present on on-premises installation of Shopware and not present on the SaaS installation due to additional security checks being implemented on the uploaded plugin files.
Description
A path traversal vulnerability allows malicious actors to access files and folders that are outside the folder structure accessible to the affected function. This vulnerability occurs when an application uses unfiltered user input to point to the path of a specific file and retrieve it. This can result in gaining read/write access to sensitive information, application code, back-end systems and other (critical) files on the operating system. In certain cases, it is even possible to store arbitrary files outside the relevant directory structure on the server in order to gain access to the server.
Applicability
The Plugin upload function in use by the Shopware application is vulnerable to path traversal. Within the on-premises version of the Shopware application users are able to extend the functionality of the application by installing ‘plugins’ also referred to as ‘apps’ or ‘extensions’. These plugins can be installed using the official store or by uploading a zip file containing the required files. To prevent path traversal the Shopware application implements a check that effectively prohibits files containing ‘..’ characters from being uploaded. During review of the source code, it was noticed that the check for the prohibited characters was only performed from the third entry (index 2) of the uploaded Zip file. This means that the second entry (index 1) within the Zip file can contain path traversal characters and thus allows files to be written in directories outside of the intended plugins folder.
To exploit this vulnerability, an admin account with permissions to upload plugins, is required.
Reproduction
To reproduce this vulnerability, the steps below can be followed. 1. Log in to an on-premises Shopware application with an admin account with permissions to upload plugins. 2. Create a malicious Zip file using the script provided in evidence 5. 3. Upload the generated malicious Zip file as a new plugin within the application 4. Access the filesystem of the Shopware application 5. Navigate to the path below: /var/www/html/custom/apps 6. Notice that an ‘evil.php’ file has been extracted within this folder.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "shopware/platform"
},
"ranges": [
{
"events": [
{
"introduced": "6.7.0.0"
},
{
"fixed": "6.7.3.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "shopware/platform"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.6.10.7"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "shopware/core"
},
"ranges": [
{
"events": [
{
"introduced": "6.7.0.0"
},
{
"fixed": "6.7.3.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "shopware/core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.6.10.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-21T18:02:14Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Impact\nMalicious actors can exploit this vulnerability to write files within arbitrary directories on the filesystem of the Shopware web container. This could allow them to gain persistent shell access by uploading a PHP-shell file to an accessible folder.\n\nIt is important to note that this vulnerability is only present on on-premises installation of Shopware and not present on the SaaS installation due to additional security checks being implemented on the uploaded plugin files.\n\n#### Description\nA path traversal vulnerability allows malicious actors to access files and folders that are outside the folder structure accessible to the affected function. This vulnerability occurs when an application uses unfiltered user input to point to the path of a specific file and retrieve it. This can result in gaining read/write access to sensitive information, application code, back-end systems and other (critical) files on the operating system. In certain cases, it is even possible to store arbitrary files outside the relevant directory structure on the server in order to gain access to the server.\n\n#### Applicability\nThe Plugin upload function in use by the Shopware application is vulnerable to path traversal.\nWithin the on-premises version of the Shopware application users are able to extend the functionality of the application by installing \u2018plugins\u2019 also referred to as \u2018apps\u2019 or \u2018extensions\u2019. These plugins can be installed using the official store or by uploading a zip file containing the required files. To prevent path traversal the Shopware application implements a check that effectively prohibits files containing \u2018..\u2019 characters from being uploaded. During review of the source code, it was noticed that the check for the prohibited characters was only performed from the third entry (index 2) of the uploaded Zip file. This means that the second entry (index 1) within the Zip file can contain path traversal characters and thus allows files to be written in\ndirectories outside of the intended plugins folder.\n\nTo exploit this vulnerability, an admin account with permissions to upload plugins, is required.\n\n#### Reproduction\nTo reproduce this vulnerability, the steps below can be followed.\n1. Log in to an on-premises Shopware application with an admin account with permissions to\nupload plugins.\n2. Create a malicious Zip file using the script provided in evidence 5.\n3. Upload the generated malicious Zip file as a new plugin within the application\n4. Access the filesystem of the Shopware application\n5. Navigate to the path below:\n/var/www/html/custom/apps\n6. Notice that an \u2018evil.php\u2019 file has been extracted within this folder.",
"id": "GHSA-6wh5-mw9h-5c3w",
"modified": "2025-10-21T18:02:14Z",
"published": "2025-10-21T18:02:14Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/shopware/shopware/security/advisories/GHSA-6wh5-mw9h-5c3w"
},
{
"type": "WEB",
"url": "https://github.com/shopware/shopware/commit/0965b35a527756faab2cec5a4ff172d79b0f99be"
},
{
"type": "PACKAGE",
"url": "https://github.com/shopware/shopware"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Shopware vulnerable to path traversal via Plugin upload"
}
GHSA-6WJ3-9V62-4M8P
Vulnerability from github – Published: 2022-05-02 06:22 – Updated: 2022-05-02 06:22Multiple directory traversal vulnerabilities in the (a) Local Storage and (b) Web SQL database implementations in WebKit in Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, allow remote attackers to create arbitrary database files via vectors involving a (1) %2f and .. (dot dot) or (2) %5c and .. (dot dot) in a URL.
{
"affected": [],
"aliases": [
"CVE-2010-1391"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2010-06-11T18:00:00Z",
"severity": "MODERATE"
},
"details": "Multiple directory traversal vulnerabilities in the (a) Local Storage and (b) Web SQL database implementations in WebKit in Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, allow remote attackers to create arbitrary database files via vectors involving a (1) %2f and .. (dot dot) or (2) %5c and .. (dot dot) in a URL.",
"id": "GHSA-6wj3-9v62-4m8p",
"modified": "2022-05-02T06:22:13Z",
"published": "2022-05-02T06:22:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2010-1391"
},
{
"type": "WEB",
"url": "https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7082"
},
{
"type": "WEB",
"url": "http://lists.apple.com/archives/security-announce/2010/Jun/msg00000.html"
},
{
"type": "WEB",
"url": "http://lists.apple.com/archives/security-announce/2010/Jun/msg00003.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2011-01/msg00006.html"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/40105"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/41856"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/43068"
},
{
"type": "WEB",
"url": "http://securitytracker.com/id?1024067"
},
{
"type": "WEB",
"url": "http://support.apple.com/kb/HT4196"
},
{
"type": "WEB",
"url": "http://support.apple.com/kb/HT4225"
},
{
"type": "WEB",
"url": "http://www.mandriva.com/security/advisories?name=MDVSA-2011:039"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/40620"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/40753"
},
{
"type": "WEB",
"url": "http://www.ubuntu.com/usn/USN-1006-1"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2010/1373"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2010/2722"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2011/0212"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2011/0552"
}
],
"schema_version": "1.4.0",
"severity": []
}
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.