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Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWc4cjQtcDk2ai14Znhj
Grav's Twig processing allowing dangerous PHP functions by default
Impact
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.
Patches
The issue was addressed by preventing dangerous functions from being called in Twig templates. A configuration option has been added to manually allow arbitrary PHP functions (system.twig.safe_functions) and filters (system.twig.safe_filters).
Futures major versions of Grav may disable this functionality by default.
Workarounds
Blocking access to the /admin path from untrusted sources will reduce the probability of exploitation.
References
- https://portswigger.net/research/server-side-template-injection
- https://blog.sonarsource.com/grav-cms-code-execution-vulnerabilities
For more information
If you have any questions or comments about this advisory, you can contact:
- The original reporters, by sending an email to vulnerability.research [at] sonarsource.com;
- The maintainers, by opening an issue on this repository.
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWc4cjQtcDk2ai14Znhj
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: over 3 years ago
Updated: almost 2 years ago
CVSS Score: 8.5
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
Identifiers: GHSA-g8r4-p96j-xfxc, CVE-2021-29440
References:
- https://github.com/getgrav/grav/security/advisories/GHSA-g8r4-p96j-xfxc
- https://packagist.org/packages/getgrav/grav
- https://nvd.nist.gov/vuln/detail/CVE-2021-29440
- http://packetstormsecurity.com/files/162987/Grav-CMS-1.7.10-Server-Side-Template-Injection.html
- https://blog.sonarsource.com/grav-cms-code-execution-vulnerabilities
- https://github.com/advisories/GHSA-g8r4-p96j-xfxc
Blast Radius: 8.1
Affected Packages
packagist:getgrav/grav
Dependent packages: 2Dependent repositories: 9
Downloads: 74,808 total
Affected Version Ranges: <= 1.7.10
Fixed in: 1.7.11
All affected versions: 0.8.0, 0.9.0, 0.9.1, 0.9.2, 0.9.3, 0.9.4, 0.9.5, 0.9.6, 0.9.7, 0.9.8, 0.9.9, 0.9.10, 0.9.11, 0.9.12, 0.9.13, 0.9.14, 0.9.15, 0.9.16, 0.9.17, 0.9.18, 0.9.19, 0.9.20, 0.9.21, 0.9.22, 0.9.23, 0.9.24, 0.9.25, 0.9.26, 0.9.27, 0.9.28, 0.9.29, 0.9.30, 0.9.31, 0.9.32, 0.9.33, 0.9.34, 0.9.35, 0.9.36, 0.9.37, 0.9.38, 0.9.39, 0.9.40, 0.9.41, 0.9.42, 0.9.43, 0.9.44, 0.9.45, 1.0.0, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.9, 1.0.10, 1.1.0, 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.1.9, 1.1.10, 1.1.11, 1.1.12, 1.1.13, 1.1.14, 1.1.15, 1.1.16, 1.1.17, 1.2.0, 1.2.1, 1.2.2, 1.2.3, 1.2.4, 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.3.7, 1.3.8, 1.3.9, 1.3.10, 1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.4.4, 1.4.5, 1.4.6, 1.4.7, 1.4.8, 1.5.0, 1.5.1, 1.5.2, 1.5.3, 1.5.4, 1.5.5, 1.5.6, 1.5.7, 1.5.8, 1.5.9, 1.5.10, 1.6.0, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.6.6, 1.6.7, 1.6.8, 1.6.9, 1.6.10, 1.6.11, 1.6.12, 1.6.13, 1.6.14, 1.6.15, 1.6.16, 1.6.17, 1.6.18, 1.6.19, 1.6.20, 1.6.21, 1.6.22, 1.6.23, 1.6.24, 1.6.25, 1.6.26, 1.6.27, 1.6.28, 1.6.29, 1.6.30, 1.6.31, 1.7.0, 1.7.1, 1.7.3, 1.7.4, 1.7.5, 1.7.6, 1.7.7, 1.7.8, 1.7.9, 1.7.10
All unaffected versions: 1.7.12, 1.7.13, 1.7.14, 1.7.15, 1.7.16, 1.7.17, 1.7.18, 1.7.19, 1.7.20, 1.7.21, 1.7.22, 1.7.23, 1.7.24, 1.7.25, 1.7.26, 1.7.27, 1.7.28, 1.7.29, 1.7.30, 1.7.31, 1.7.32, 1.7.33, 1.7.34, 1.7.35, 1.7.36, 1.7.37, 1.7.38, 1.7.39, 1.7.40, 1.7.41, 1.7.42, 1.7.43, 1.7.44, 1.7.45, 1.7.46, 1.7.47, 1.7.48