Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)

[ Description ]Official description

Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. 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 < 13.0.0)

[ Packages ]Affected open-source packages

• Pillow pipAffected < 13.0.0 · fixed in 13.0.0 · GHSA-p8hx-v2p6-rp84

[ References ]References

• github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48
• github.com/python-pillow/Pillow/pull/10011
• github.com/python-pillow/Pillow/releases/tag/13.0.0
• github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84