REDAXO: Stored XSS in Mediapool Sync Page via Unescaped Filesystem Filenames

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

REDAXO is a PHP-based content management system. Prior to 5.21.2, redaxo/src/addons/mediapool/pages/sync.php inserts filenames held in $diffFiles from the media filesystem into the Mediapool Sync page without rex_escape(). An attacker who can place an unregistered file with HTML metacharacters in the media directory can execute script in the browser of a backend user with media[sync] permission when that user opens the Sync page, enabling session theft or unauthorized backend actions. This issue is fixed in version 5.21.2.

[ Fixes ]Fixes and patches

• redaxo/source 5.21.2Fixed version · GitHub Advisories · composer package redaxo/source: upgrade to 5.21.2 or later (affected <= 5.21.1)
• Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
• Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ Packages ]Affected open-source packages

• redaxo/source composerAffected <= 5.21.1 · fixed in 5.21.2 · GHSA-w998-qmw9-mf4m

[ References ]References

• github.com/redaxo/core/commit/2daaa3a30570bc76a82f63fd21fb8c9c2cd5dc7cPatch
• github.com/redaxo/core/pull/6581Issue TrackingPatch
• github.com/redaxo/core/releases/tag/5.21.2Release Notes
• github.com/redaxo/core/security/advisories/GHSA-w998-qmw9-mf4mExploitVendor Advisory