Pillow: P;2L and P;4L decoders may read 1 to 3 bytes past the passed buffer size

[ 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 P;2L and P;4L raw decoders can read past the end of an input buffer. ImagingRawDecode calculates a packed-pixel row size, while the unpackers read separately padded bit planes. A caller can supply a buffer and image dimensions whose accepted size is smaller than the unpacker's actual footprint. This can disclose up to three adjacent heap bytes in output pixels or crash the process. 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-4558-3h8r-v8xp

[ References ]References

• github.com/python-pillow/Pillow/commit/392ee6f0d19a4adb766a63e9a99f3c28193b8d31
• github.com/python-pillow/Pillow/releases/tag/13.0.0
• github.com/python-pillow/Pillow/security/advisories/GHSA-4558-3h8r-v8xp