Winter CMS versions before 1.2.13 contain an incomplete fix for a Twig sandbox escape vulnerability in System\\Twig\\SecurityPolicy that allows authenticated backend users with template-editing permissions to bypass sandbox restrictions. Attackers can exploit method forwarding through Eloquent models and query builders using methods like saveQuietly(), deleteQuietly(), increment(), decrement(), and newQuery() to read and modify arbitrary database records, execute arbitrary SQL, and achieve remote code execution by injecting PHP into template code sections.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://github.com/wintercms/winter/commit/725bbcda232466f7f71381c271c6916573d5…
disclosure@vulncheck.com
https://github.com/wintercms/winter/security/advisories/GHSA-8cfw-pcwh-v63w
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/winter-cms-before-twig-sandbox-escape-via-…
disclosure@vulncheck.com