Pillow: NULL pointer dereference in Image.merge via an unvalidated band 0

[ Why it matters ]Priority signals

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

[ Description ]Official description

Pillow is a Python imaging library. From 12.0.0 until 13.0.0, Pillow's Image.merge() can dereference a null image8 plane. Validation skips the first input band, allowing a 32-bit integer or floating-point image backed by image32 storage to be merged as a narrower multiband image. A crafted IPTC file can reach this path when an application opens and loads it, or a caller can invoke Image.merge() directly with such a first band. 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 >= 12.0.0, < 13.0.0)

[ Packages ]Affected open-source packages

• pillow pipAffected >= 12.0.0, < 13.0.0 · fixed in 13.0.0 · GHSA-cp9v-662q-vvx9

[ References ]References

• github.com/python-pillow/Pillow/commit/b6ee66e8b2c2c0932bdf65f963268d9f2927ef86
• github.com/python-pillow/Pillow/releases/tag/13.0.0
• github.com/python-pillow/Pillow/security/advisories/GHSA-cp9v-662q-vvx9