RCE in Getgrav Grav
CVE-2023-34253
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.021 (80.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 80.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000
Affected products
- Getgrav Grav — versions < 1.7.42
Weakness classification (CWE)
References
- github.com/getgrav/grav/security/advisories/GHSA-j3v8-v77f-fvgm (Exploit, Vendor Advisory)
- github.com/getgrav/grav/commit/71bbed12f950de8335006d7f91112263d8504f1b (Patch)
- github.com/getgrav/grav/blob/1.7.40/system/src/Grav/Common/Utils.php (Issue Tracking)
- huntr.dev/bounties/3ef640e6-9e25-4ecb-8ec1-64311d63fe66/ (Exploit, Third Party Advisory)
- www.github.com/getgrav/grav/commit/9d6a2dba09fd4e56f5cdfb9a399caea355bfeb83 (Patch)
Frequently asked questions
- What is CVE-2023-34253?
- CVE-2023-34253 is a high-severity vulnerability in Getgrav Grav, classified under Incomplete List of Disallowed Inputs. CVSS score: 8.8/10. Published 2023-06-14.
- How severe is CVE-2023-34253?
- High severity. CVSS v3 base score is 8.8 out of 10.