PIL.ImageMath.eval in Pillow before 9.0.0 allows evaluation of arbitrary expressions, such as ones that use the Python exec method ImageMath.eval("exec(exit())").
While Pillow 9.0.0 restricted top-level builtins available to PIL.ImageMath.eval(), it did not prevent builtins available to lambda expressions. These are now also restricted in 9.0.1.
References
- https://nvd.nist.gov/vuln/detail/CVE-2022-22817
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#restrict-builtins-available-to-imagemath-eval
- https://lists.debian.org/debian-lts-announce/2022/01/msg00018.html
- https://www.debian.org/security/2022/dsa-5053
- https://github.com/python-pillow/Pillow/commit/8531b01d6cdf0b70f256f93092caa2a5d91afc11
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.1.html#security
- https://github.com/advisories/GHSA-8vj2-vxx3-667w