REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/redaxo/core/commit/462e36896bb65d292ba22d711044c23c9cfb0340
security-advisories@github.com
https://github.com/redaxo/core/pull/6538
security-advisories@github.com
https://github.com/redaxo/core/releases/tag/5.21.1
security-advisories@github.com
https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25
security-advisories@github.com