Twig may load a template outside a configured directory when using the filesystem loader

Description

Description

When using the filesystem loader to load templates for which the name is a user input, it is possible to use the source or include statement to read arbitrary files from outside the templates directory when using a namespace like @somewhere/../some.file (in such a case, validation is bypassed).

Resolution

We fixed validation for such template names.

Even if the 1.x branch is not maintained anymore, a new version has been released.

Credits

We would like to thank Dariusz Tytko for reporting the issue and Fabien Potencier for fixing the issue.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2022-09-30 05:29:36 UTC
Updated
2023-01-27 05:03:12 UTC
GitHub reviewed
2022-09-30 05:29:36 UTC
NVD published
2022-09-28

EPSS Score

Score Percentile
9.50% 92.77%

CVSS Scores

Base score Version Severity Vector
7.5 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected packages (3)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
composer twig/twig >= 1.0.0, < 1.44.7 1.44.7
composer twig/twig >= 2.0.0, < 2.15.3 2.15.3
composer twig/twig >= 3.0.0, < 3.4.3 3.4.3

References

cvelogic Threat Intelligence