Pillow: NULL dereference in ImagingExpand via rank filters on zero-size images

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Pillow is a Python imaging library. Prior to 13.0.0, Pillow's rank-based filters can dereference invalid image storage for a zero-size image. ImagingExpand() allocates a non-empty output and then faults while replicating edges by reading the first pixel from empty input storage; ImagingRankFilter is never reached. An attacker can supply or cause creation of a zero-size image to an application that applies a rank, median, minimum, or maximum filter. This causes a native process crash. This issue is fixed in version 13.0.0.

[ Fixes ]Fixes and patches

• Pillow 13.0.0Fixed version · GitHub Advisories · pip package Pillow: upgrade to 13.0.0 or later (affected <= 12.3.0)

[ Packages ]Affected open-source packages

• Pillow pipAffected <= 12.3.0 · fixed in 13.0.0 · GHSA-27h8-gf7j-v5hc

[ References ]References

• github.com/python-pillow/Pillow/commit/443e3130a8c11594fd0e296afad497e11e678961
• github.com/python-pillow/Pillow/releases/tag/13.0.0
• github.com/python-pillow/Pillow/security/advisories/GHSA-27h8-gf7j-v5hc