2025-03-05 20:40:06
GitHub_M
PUBLISHED
Jinja is an extensible templating engine. Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinjas sandbox does catch calls to str.format and ensures they dont escape the sandbox. However, its possible to use the |attr filter to get a reference to a strings plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environments attribute lookup. This vulnerability is fixed in 3.1.6.