CVE-2023-37897
Grav is subject to a server side template injection (SSTI) vulnerability.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.81%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Grav is a file-based Web-platform built in PHP. Grav is subject to a server side template injection (SSTI) vulnerability. The fix for another SSTI vulnerability using `|map`, `|filter` and `|reduce` twigs implemented in the commit `71bbed1` introduces bypass of the denylist due to incorrect return value from `isDangerousFunction()`, which allows to execute the payload prepending double backslash (`\\`). The `isDangerousFunction()` check in version 1.7.42 and onwards retuns `false` value instead of `true` when the `\` symbol is found in the `$name`. This vulnerability can be exploited if the attacker has access to: 1. an Administrator account, or 2. a non-administrator, user account that has Admin panel access and Create/Update page permissions. A fix for this vulnerability has been introduced in commit `b4c6210` and is included in release version `1.7.42.2`. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.81% probability · 86th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-74, CWE-393
- Affected
- getgrav/grav
- Source
- security-advisories@github.com
References
- https://github.com/getgrav/grav/commit/71bbed12f950de8335006d7f91112263d8504f1bProduct
- https://github.com/getgrav/grav/commit/b4c62101a43051fc7f5349c7d0a5b6085375c1d7Patch
- https://github.com/getgrav/grav/security/advisories/GHSA-9436-3gmp-4f53Exploit, Mitigation, Vendor Advisory
- https://github.com/getgrav/grav/commit/71bbed12f950de8335006d7f91112263d8504f1bProduct
- https://github.com/getgrav/grav/commit/b4c62101a43051fc7f5349c7d0a5b6085375c1d7Patch
- https://github.com/getgrav/grav/security/advisories/GHSA-9436-3gmp-4f53Exploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.