CVE-2021-29440 in the critical feed json
Twig allowing dangerous PHP functions by default
published 2021-04-13 5 y ago modified 2026-06-17 4 mo ago also GHSA-g8r4-p96j-xfxc , EUVD-2021-0824
- cvss
- 8.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 29.9%
- EPSS 29.9% chance of exploitation in 30 days, percentile 98%
- public exploits
- 1
- Exploit-DB
Summary
Grav is a file based Web-platform. Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance. The issue was addressed in version 1.7.11.
Patch / fix
- packagist getgrav/grav 1.7.11
- getgrav grav 1.7.11
Timeline
- Published
- First public exploit (EDB-49961)
Exploit prediction
29.90% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- EDB-49961 Grav CMS 1.7.10 - Server-Side Template Injection (SSTI) (Authenticated) webapps, 2021-06-07
- packetstormsecurity.com http://packetstormsecurity.com/files/162987/Grav-CMS-1.7.10-Server-Side-Template-Injection.html referenced PoC, tagged "exploit" by a source, unverified
- blog.sonarsource.com https://blog.sonarsource.com/grav-cms-code-execution-vulnerabilities referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.4 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H |
| NVD | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.5 | AV:N/AC:L/Au:S/C:P/I:P/A:P |
| GitHub | 3.1 | 8.4 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | getgrav/grav | <1.7.11 |
1.7.11 |
Affected products
- getgrav grav
Classification
- Weakness
-
- CWE-94 Improper Control of Generation of Code
References
-
packetstormsecurity.com
/files/162987/Grav-CMS-1.7.10-Server-Side-Template-Injection.html
web, exploit, third-party-advisory, vdb-entry
-
blog.sonarsource.com
/grav-cms-code-execution-vulnerabilities
web, exploit, third-party-advisory
-
github.com
/getgrav/grav/security/advisories/GHSA-g8r4-p96j-xfxc
web, third-party-advisory
-
packagist.org
/packages/getgrav/grav
web, product, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-29440
advisory
Sources
- CVE List CVE-2021-29440
- GitHub Advisory GHSA-g8r4-p96j-xfxc
- NVD CVE-2021-29440
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.