CWE-289: Authentication Bypass by Alternate Name

The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.

Consequences

• Access Control: Bypass Protection Mechanism

How to prevent it

• Architecture and Design: Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
• Implementation: 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.
• Implementation: 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.

Recent advisories

• GHSA-9r87-mvcw-x35f — Coder vulnerable to OIDC account takeover via email-based user matching and email_verified bypass
• GHSA-9cr8-q42q-g8m7 — Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts
• GHSA-pjwm-pj3p-43mv — axios's shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718)
• GHSA-5m6w-wvh7-57vm — Traefik: Pre-authentication decision bypass due to forwarded alias spoofing
• GHSA-g7cr-9h7q-4qxq — OpenClaw's MS Teams sender allowlist bypass when route allowlist is configured and sender allowlist is empty
• GHSA-mwxv-35wr-4vvj — OpenClaw has gateway plugin auth bypass via encoded dot-segment traversal in protected /api/channels paths
• GHSA-8v5q-rhf3-jphm — Spring Security annotation detection mechanism has authorization bypass
• DRUPAL-CORE-2024-004 — Drupal core Access bypass
• GHSA-xfv7-h2qg-rjm7 — Moodle Lesson activity password bypass through PHP loose comparison
• GHSA-36qh-35cm-5w2w — Authentication Bypass by Alternate Name in Apache Tomcat

All advisories for CWE-289