Vulnerability Description
Grav is a flat-file content management system. Prior to version 1.7.42, the denylist introduced in commit 9d6a2d to prevent dangerous functions from being executed via injection of malicious templates was insufficient and could be easily subverted in multiple ways -- (1) using unsafe functions that are not banned, (2) using capitalised callable names, and (3) using fully-qualified names for referencing callables. Consequently, a low privileged attacker with login access to Grav Admin panel and page creation/update permissions is able to inject malicious templates to obtain remote code execution. A patch in version 1.7.42 improves the denylist.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Getgrav | Grav | < 1.7.42 |
Related Weaknesses (CWE)
References
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L19Issue Tracking
- https://github.com/getgrav/grav/commit/71bbed12f950de8335006d7f91112263d8504f1bPatch
- https://github.com/getgrav/grav/security/advisories/GHSA-j3v8-v77f-fvgmExploitVendor Advisory
- https://huntr.dev/bounties/3ef640e6-9e25-4ecb-8ec1-64311d63fe66/ExploitThird Party Advisory
- https://www.github.com/getgrav/grav/commit/9d6a2dba09fd4e56f5cdfb9a399caea355bfePatch
- https://github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php#L19Issue Tracking
- https://github.com/getgrav/grav/commit/71bbed12f950de8335006d7f91112263d8504f1bPatch
- https://github.com/getgrav/grav/security/advisories/GHSA-j3v8-v77f-fvgmExploitVendor Advisory
- https://huntr.dev/bounties/3ef640e6-9e25-4ecb-8ec1-64311d63fe66/ExploitThird Party Advisory
- https://www.github.com/getgrav/grav/commit/9d6a2dba09fd4e56f5cdfb9a399caea355bfePatch
FAQ
What is CVE-2023-34253?
CVE-2023-34253 is a vulnerability with a CVSS score of 8.8 (HIGH). Grav is a flat-file content management system. Prior to version 1.7.42, the denylist introduced in commit 9d6a2d to prevent dangerous functions from being executed via injection of malicious templates...
How severe is CVE-2023-34253?
CVE-2023-34253 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2023-34253?
Check the references section above for vendor advisories and patch information. Affected products include: Getgrav Grav.