WWBN AVideo up to 29.0 Locale Save Endpoint locale/save.php fwrite flag path traversal

Summaryinfo

A vulnerability classified as critical has been found in WWBN AVideo up to 29.0. Affected by this vulnerability is the function fwrite of the file locale/save.php of the component Locale Save Endpoint. This manipulation of the argument flag causes path traversal. This vulnerability is tracked as CVE-2026-40909. The attack is possible to be carried out remotely. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in WWBN AVideo up to 29.0. It has been declared as critical. Affected by this vulnerability is the function fwrite of the file locale/save.php of the component Locale Save Endpoint. The manipulation of the argument flag with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. 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. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

WWBN AVideo is an open source video platform. In versions 29.0 and prior, the locale save endpoint (`locale/save.php`) constructs a file path by directly concatenating `$_POST['flag']` into the path at line 30 without any sanitization. The `$_POST['code']` parameter is then written verbatim to that path via `fwrite()` at line 40. An admin attacker (or any user who can CSRF an admin, since no CSRF token is checked and cookies use `SameSite=None`) can traverse out of the `locale/` directory and write arbitrary `.php` files to any writable location on the filesystem, achieving Remote Code Execution. Commit 57f89ffbc27d37c9d9dd727212334846e78ac21a fixes the issue.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-40909 since 04/15/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are required for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

By approaching the search of inurl:locale/save.php it is possible to find vulnerable targets with Google Hacking.

Applying the patch 57f89ffbc27d37c9d9dd727212334846e78ac21a is able to eliminate this problem. The bugfix is ready for download at github.com.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• WWBN

Name

• AVideo

Version

• 29.0

License

• open-source

Website

• Product: https://github.com/WWBN/AVideo/

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