Описание
Astro has an Authentication Bypass via Double URL Encoding, a bypass for CVE-2025-64765
Authentication Bypass via Double URL Encoding in Astro
Bypass for CVE-2025-64765 / GHSA-ggxq-hp9w-j794
Summary
A double URL encoding bypass allows any unauthenticated attacker to bypass path-based authentication checks in Astro middleware, granting unauthorized access to protected routes. While the original CVE-2025-64765 (single URL encoding) was fixed in v5.15.8, the fix is insufficient as it only decodes once. By using double-encoded URLs like /%2561dmin instead of /%61dmin, attackers can still bypass authentication and access protected resources such as /admin, /api/internal, or any route protected by middleware pathname checks.
Fix
A more secure fix is just decoding once, then if the request has a %xx format, return a 400 error by using something like :
Ссылки
- https://github.com/withastro/astro/security/advisories/GHSA-ggxq-hp9w-j794
- https://github.com/withastro/astro/security/advisories/GHSA-whqg-ppgf-wp8c
- https://nvd.nist.gov/vuln/detail/CVE-2025-64765
- https://nvd.nist.gov/vuln/detail/CVE-2025-66202
- https://github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58ce
Пакеты
astro
< 5.15.8
5.15.8
Связанные уязвимости
Astro is a web framework. Versions 5.15.7 and below have a double URL encoding bypass which allows any unauthenticated attacker to bypass path-based authentication checks in Astro middleware, granting unauthorized access to protected routes. While the original CVE-2025-64765 was fixed in v5.15.8, the fix is insufficient as it only decodes once. By using double-encoded URLs, attackers can still bypass authentication and access any route protected by middleware pathname checks. This issue is fixed in version 5.15.8.