Common Weakness Enumeration
CWE-35
AllowedPath Traversal: '.../...//'
Abstraction: Variant · Status: Incomplete
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '.../...//' (doubled triple dot slash) sequences that can resolve to a location that is outside of that directory.
358 vulnerabilities reference this CWE, most recent first.
GHSA-3MG7-9VMR-P6HR
Vulnerability from github – Published: 2025-10-07 21:31 – Updated: 2025-10-07 21:31
VLAI
Details
Dell PowerProtect Data Domain with Data Domain Operating System (DD OS) of Feature Release versions 7.7.1.0 through 8.3.0.15, LTS2025 release version 8.3.1.0, LTS2024 release versions 7.13.1.0 through 7.13.1.30, LTS 2023 release versions 7.10.1.0 through 7.10.1.60, contain a Path Traversal: '.../...//' vulnerability. A low privileged attacker with remote access could potentially exploit this vulnerability, leading to Information exposure.
Severity
6.5 (Medium)
{
"affected": [],
"aliases": [
"CVE-2025-43907"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-07T19:15:37Z",
"severity": "MODERATE"
},
"details": "Dell PowerProtect Data Domain with Data Domain Operating System (DD OS) of Feature Release versions 7.7.1.0 through 8.3.0.15, LTS2025 release version 8.3.1.0, LTS2024 release versions 7.13.1.0 through 7.13.1.30, LTS 2023 release versions 7.10.1.0 through 7.10.1.60, contain a Path Traversal: \u0027.../...//\u0027 vulnerability. A low privileged attacker with remote access could potentially exploit this vulnerability, leading to Information exposure.",
"id": "GHSA-3mg7-9vmr-p6hr",
"modified": "2025-10-07T21:31:06Z",
"published": "2025-10-07T21:31:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-43907"
},
{
"type": "WEB",
"url": "https://www.dell.com/support/kbdoc/en-us/000376224/dsa-2025-333-security-update-for-dell-powerprotect-data-domain-multiple-vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3Q34-RX83-R6MQ
Vulnerability from github – Published: 2026-04-25 23:30 – Updated: 2026-05-12 13:29
VLAI
Summary
Heimdall has an authorization bypass via path normalization mismatch
Details
Summary
Heimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to RFC 3986, Section 6.2.2.3. This discrepancy can result in heimdall authorizing a request for one path (e.g., /user/../admin, or URL-encoded variants such as /user/%2e%2e/admin or /user/%2e%2e%2fadmin. The latter would require the allow_encoded_slashes option to be set to on or no_decode.) while the downstream ultimately processes a different, normalized path (/admin).
Details
This vulnerability can be exploited by an adversary if rule matching is performed using free (named or unnamed) wildcards without further constraints, as shown in the example snippets below.
id: rule-1
match:
routes:
- path: /user/**
execute: # configured to require authentication and authorization
# ...
id: rule-2
match:
routes:
- path: /public/**
execute: # configured to allow anonymous access
# ...
If an adversary sends a request to /public/../user/whatever, rule-2 will be matched and executed. The downstream service may, however, normalize the request path and interpret it as /user/whatever.
Impact
Bypass of access control policies enforced by heimdall may lead to the following consequences:
- Access to or modification of data that should be restricted
- Invocation of functionality that is expected to require authentication or authorization
- In certain configurations, escalation of privileges depending on the exposed functionality
Workarounds
- Normalize HTTP paths or reject HTTP paths containing relative path expressions in the layers in front of Heimdall - this is good practice anyway. Some proxies do that by default, such as Traefik; others, such as Envoy, require additional configuration (for Envoy see
normalize_path). - Include the ID of the rule expected to be executed in the JWT issued by heimdall and check that value in the consuming project's service.
Severity
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/dadrus/heimdall"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.17.14"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-42274"
],
"database_specific": {
"cwe_ids": [
"CWE-35",
"CWE-436"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-25T23:30:46Z",
"nvd_published_at": "2026-05-08T04:16:22Z",
"severity": "HIGH"
},
"details": "### Summary\n\nHeimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to [RFC 3986, Section 6.2.2.3](https://www.rfc-editor.org/rfc/rfc3986#section-6.2.2.3). This discrepancy can result in heimdall authorizing a request for one path (e.g., `/user/../admin`, or URL-encoded variants such as `/user/%2e%2e/admin` or `/user/%2e%2e%2fadmin`. The latter would require the `allow_encoded_slashes` option to be set to `on` or `no_decode`.) while the downstream ultimately processes a different, normalized path (`/admin`).\n\n### Details\n\nThis vulnerability can be exploited by an adversary if rule matching is performed using free (named or unnamed) wildcards without further constraints, as shown in the example snippets below.\n\n```yaml\nid: rule-1\nmatch:\n routes:\n - path: /user/**\nexecute: # configured to require authentication and authorization\n # ...\n```\n\n```yaml\nid: rule-2\nmatch:\n routes:\n - path: /public/**\nexecute: # configured to allow anonymous access\n # ...\n```\n\nIf an adversary sends a request to `/public/../user/whatever`, rule-2 will be matched and executed. The downstream service may, however, normalize the request path and interpret it as `/user/whatever`.\n\n### Impact\n\nBypass of access control policies enforced by heimdall may lead to the following consequences:\n\n* Access to or modification of data that should be restricted\n* Invocation of functionality that is expected to require authentication or authorization\n* In certain configurations, escalation of privileges depending on the exposed functionality\n\n### Workarounds\n\n* Normalize HTTP paths or reject HTTP paths containing relative path expressions in the layers in front of Heimdall - this is good practice anyway. Some proxies do that by default, such as Traefik; others, such as Envoy, require additional configuration (for Envoy see [`normalize_path`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto#envoy-v3-api-field-extensions-filters-network-http-connection-manager-v3-httpconnectionmanager-normalize-path)).\n* Include the ID of the rule expected to be executed in the JWT issued by heimdall and check that value in the consuming project\u0027s service.",
"id": "GHSA-3q34-rx83-r6mq",
"modified": "2026-05-12T13:29:02Z",
"published": "2026-04-25T23:30:46Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/dadrus/heimdall/security/advisories/GHSA-3q34-rx83-r6mq"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42274"
},
{
"type": "WEB",
"url": "https://github.com/dadrus/heimdall/pull/3209"
},
{
"type": "WEB",
"url": "https://github.com/dadrus/heimdall/commit/b5dfa484b7a8c2ce6d8691c026f9da867719947a"
},
{
"type": "PACKAGE",
"url": "https://github.com/dadrus/heimdall"
},
{
"type": "WEB",
"url": "https://github.com/dadrus/heimdall/releases/tag/v0.17.14"
},
{
"type": "WEB",
"url": "https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto#envoy-v3-api-field-extensions-filters-network-http-connection-manager-v3-httpconnectionmanager-normalize-path"
},
{
"type": "WEB",
"url": "https://www.rfc-editor.org/rfc/rfc3986#section-6.2.2.3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Heimdall has an authorization bypass via path normalization mismatch"
}
GHSA-3Q4V-7RF3-MXGQ
Vulnerability from github – Published: 2025-03-03 15:31 – Updated: 2026-04-01 18:33
VLAI
Details
Path Traversal vulnerability in NotFound GPX Viewer allows Path Traversal. This issue affects GPX Viewer: from n/a through 2.2.11.
Severity
4.9 (Medium)
{
"affected": [],
"aliases": [
"CVE-2025-27274"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-03-03T14:15:58Z",
"severity": "MODERATE"
},
"details": "Path Traversal vulnerability in NotFound GPX Viewer allows Path Traversal. This issue affects GPX Viewer: from n/a through 2.2.11.",
"id": "GHSA-3q4v-7rf3-mxgq",
"modified": "2026-04-01T18:33:55Z",
"published": "2025-03-03T15:31:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-27274"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/wordpress/plugin/gpx-viewer/vulnerability/wordpress-gpx-viewer-plugin-2-2-11-path-traversal-vulnerability?_s_id=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-3WJP-774C-XVQR
Vulnerability from github – Published: 2026-07-02 12:31 – Updated: 2026-07-02 12:31
VLAI
Details
Customer Path Traversal in Tax Exempt for WooCommerce <= 1.9.3 versions.
Severity
6.5 (Medium)
{
"affected": [],
"aliases": [
"CVE-2026-49779"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-02T12:17:29Z",
"severity": "MODERATE"
},
"details": "Customer Path Traversal in Tax Exempt for WooCommerce \u003c= 1.9.3 versions.",
"id": "GHSA-3wjp-774c-xvqr",
"modified": "2026-07-02T12:31:00Z",
"published": "2026-07-02T12:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49779"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/wordpress/plugin/woocommerce-tax-exempt-plugin/vulnerability/wordpress-tax-exempt-for-woocommerce-plugin-1-9-3-path-traversal-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-3X3C-PJW5-PJR2
Vulnerability from github – Published: 2023-12-01 00:31 – Updated: 2023-12-01 00:31
VLAI
Details
In Delta Electronics InfraSuite Device Master v.1.0.7, a vulnerability exists that allows an attacker to write to any file to any location of the filesystem, which could lead to remote code execution.
Severity
8.8 (High)
{
"affected": [],
"aliases": [
"CVE-2023-46690"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-11-30T22:15:08Z",
"severity": "HIGH"
},
"details": "In Delta Electronics InfraSuite Device Master v.1.0.7, a vulnerability exists that allows an attacker to write to any file to any location of the filesystem, which could lead to remote code execution.",
"id": "GHSA-3x3c-pjw5-pjr2",
"modified": "2023-12-01T00:31:00Z",
"published": "2023-12-01T00:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-46690"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-23-331-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-4586-432G-JMVG
Vulnerability from github – Published: 2026-02-17 21:31 – Updated: 2026-03-11 18:30
VLAI
Details
Rocket TRUfusion Enterprise through 7.10.5 exposes the endpoint at /axis2/services/WsPortalV6UpDwAxis2Impl to authenticated users to be able to upload files. However, the application doesn't properly sanitize the jobDirectory parameter, which allows path traversal sequences to be included. This allows writing files to arbitrary local filesystem locations and may subsequently lead to remote code execution.
Severity
9.9 (Critical)
{
"affected": [],
"aliases": [
"CVE-2025-59793"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-17T19:21:54Z",
"severity": "CRITICAL"
},
"details": "Rocket TRUfusion Enterprise through 7.10.5 exposes the endpoint at /axis2/services/WsPortalV6UpDwAxis2Impl to authenticated users to be able to upload files. However, the application doesn\u0027t properly sanitize the jobDirectory parameter, which allows path traversal sequences to be included. This allows writing files to arbitrary local filesystem locations and may subsequently lead to remote code execution.",
"id": "GHSA-4586-432g-jmvg",
"modified": "2026-03-11T18:30:25Z",
"published": "2026-02-17T21:31:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59793"
},
{
"type": "WEB",
"url": "https://www.rcesecurity.com"
},
{
"type": "WEB",
"url": "https://www.rcesecurity.com/advisories/cve-2025-59793"
},
{
"type": "WEB",
"url": "https://www.rocketsoftware.com/en-us/products/b2b-supply-chain-integration/trufusion"
},
{
"type": "WEB",
"url": "https://www.rocketsoftware.com/products/rocket-b2b-supply-chain-integration/rocket-trufusion-enterprise"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-485R-PHMQ-84VW
Vulnerability from github – Published: 2025-04-17 00:30 – Updated: 2025-04-17 00:30
VLAI
Details
Overview
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '.../...//' (doubled triple dot slash) sequences that can resolve to a location that is outside of that directory. (CWE-35)
Description
Hitachi Vantara Pentaho Data Integration & Analytics versions before 10.2.0.2, including 9.3.x and 8.3.x, do not sanitize a user input used as a file path through the UploadFile service.
Impact
This allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.
Severity
6.8 (Medium)
{
"affected": [],
"aliases": [
"CVE-2025-24908"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-04-16T23:15:45Z",
"severity": "MODERATE"
},
"details": "Overview \n\n\n\n\u00a0\n\n\n\nThe product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize \u0027.../...//\u0027 (doubled triple dot slash) sequences that can resolve to a location that is outside of that directory. (CWE-35) \n\n\n\n\u00a0\n\n\n\nDescription \n\n\n\n\u00a0\n\n\n\nHitachi Vantara Pentaho Data Integration \u0026 Analytics versions before 10.2.0.2, including 9.3.x and 8.3.x, do not sanitize a user input used as a file path through the UploadFile service. \n\n\n\n\u00a0\n\n\n\nImpact \n\n\n\n\u00a0\n\n\n\nThis allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.",
"id": "GHSA-485r-phmq-84vw",
"modified": "2025-04-17T00:30:26Z",
"published": "2025-04-17T00:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-24908"
},
{
"type": "WEB",
"url": "https://support.pentaho.com/hc/en-us/articles/35783399569421--Resolved-Hitachi-Vantara-Pentaho-Data-Integration-Analytics-Path-Traversal-Versions-before-10-2-0-2-including-9-3-x-Impacted-CVE-2025-24908"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-4CCX-55GP-X5QQ
Vulnerability from github – Published: 2024-11-19 00:32 – Updated: 2026-04-01 18:32
VLAI
Details
: Path Traversal: '.../...//' vulnerability in CYAN Backup allows Path Traversal.This issue affects CYAN Backup: from n/a through 2.5.3.
Severity
4.9 (Medium)
{
"affected": [],
"aliases": [
"CVE-2024-52390"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-11-18T22:15:08Z",
"severity": "MODERATE"
},
"details": ": Path Traversal: \u0027.../...//\u0027 vulnerability in CYAN Backup allows Path Traversal.This issue affects CYAN Backup: from n/a through 2.5.3.",
"id": "GHSA-4ccx-55gp-x5qq",
"modified": "2026-04-01T18:32:26Z",
"published": "2024-11-19T00:32:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-52390"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Plugin/cyan-backup/vulnerability/wordpress-cyan-backup-plugin-2-5-3-arbitrary-file-download-vulnerability?_s_id=cve"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/vulnerability/cyan-backup/wordpress-cyan-backup-plugin-2-5-3-arbitrary-file-download-vulnerability?_s_id=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-4CH2-HCMC-WJW8
Vulnerability from github – Published: 2026-06-15 21:30 – Updated: 2026-06-15 21:30
VLAI
Details
Unauthenticated Path Traversal in FastDup <= 2.7.2 versions.
Severity
9.6 (Critical)
{
"affected": [],
"aliases": [
"CVE-2026-52703"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-15T21:17:24Z",
"severity": "CRITICAL"
},
"details": "Unauthenticated Path Traversal in FastDup \u003c= 2.7.2 versions.",
"id": "GHSA-4ch2-hcmc-wjw8",
"modified": "2026-06-15T21:30:50Z",
"published": "2026-06-15T21:30:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52703"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/wordpress/plugin/fastdup/vulnerability/wordpress-fastdup-plugin-2-7-2-path-traversal-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-4GH8-CR63-898J
Vulnerability from github – Published: 2025-11-06 18:32 – Updated: 2026-01-20 15:31
VLAI
Details
Path Traversal: '.../...//' vulnerability in Dmitry V. (CEO of "UKR Solution") Barcode Scanner with Inventory & Order Manager barcode-scanner-lite-pos-to-manage-products-inventory-and-orders allows Path Traversal.This issue affects Barcode Scanner with Inventory & Order Manager: from n/a through <= 1.10.4.
Severity
7.2 (High)
{
"affected": [],
"aliases": [
"CVE-2025-58972"
],
"database_specific": {
"cwe_ids": [
"CWE-35"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-06T16:16:00Z",
"severity": "HIGH"
},
"details": "Path Traversal: \u0027.../...//\u0027 vulnerability in Dmitry V. (CEO of \"UKR Solution\") Barcode Scanner with Inventory \u0026 Order Manager barcode-scanner-lite-pos-to-manage-products-inventory-and-orders allows Path Traversal.This issue affects Barcode Scanner with Inventory \u0026 Order Manager: from n/a through \u003c= 1.10.4.",
"id": "GHSA-4gh8-cr63-898j",
"modified": "2026-01-20T15:31:49Z",
"published": "2025-11-06T18:32:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-58972"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/Wordpress/Plugin/barcode-scanner-lite-pos-to-manage-products-inventory-and-orders/vulnerability/wordpress-barcode-scanner-with-inventory-order-manager-plugin-1-10-4-path-traversal-vulnerability?_s_id=cve"
},
{
"type": "WEB",
"url": "https://vdp.patchstack.com/database/Wordpress/Plugin/barcode-scanner-lite-pos-to-manage-products-inventory-and-orders/vulnerability/wordpress-barcode-scanner-with-inventory-order-manager-plugin-1-10-4-path-traversal-vulnerability"
},
{
"type": "WEB",
"url": "https://vdp.patchstack.com/database/Wordpress/Plugin/barcode-scanner-lite-pos-to-manage-products-inventory-and-orders/vulnerability/wordpress-barcode-scanner-with-inventory-order-manager-plugin-1-10-4-path-traversal-vulnerability?_s_id=cve"
}
],
"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"
}
]
}
Mitigation MIT-5.1
Implementation
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, the ".../...//" manipulation is useful for bypassing some path traversal protection schemes. If "../" sequences are removed from the ".../...//" string in a sequential fashion (as some regular expression engines and other algorithms operate) the string can collapse into the unsafe "../" value (CWE-182). Removing the first "../" yields "....//" and the second removal yields "../".
Mitigation MIT-20
Implementation
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.
No CAPEC attack patterns related to this CWE.