CVE-2023-36807

Name	CVE-2023-36807
Description	pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. In version 2.10.5 an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case if the user extracted metadata from such a malformed PDF. Versions prior to 2.10.5 throw an error, but do not hang forever. This issue was fixed with https://github.com/py-pdf/pypdf/pull/1331 which has been included in release 2.10.6. Users are advised to upgrade. Users unable to upgrade should modify `PyPDF2/generic/_data_structures.py::read_object` to an an error throwing case. See GHSA-hm9v-vj3r-r55m for details.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pypdf2 (PTS)	buster	1.26.0-2	fixed
	buster (security)	1.26.0-2+deb10u2	fixed
	bullseye	1.26.0-4	fixed
	bookworm	2.12.1-3+deb12u1	fixed
	sid	2.12.1-4	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
pypdf2	source	buster	(not affected)
pypdf2	source	bullseye	(not affected)
pypdf2	source	(unstable)	2.10.7-1

Notes

[bullseye] - pypdf2 <not-affected> (only version 2.10.5 is affected)
[buster] - pypdf2 <not-affected> (only version 2.10.5 is affected)
https://github.com/py-pdf/pypdf/security/advisories/GHSA-hm9v-vj3r-r55m
https://github.com/py-pdf/pypdf/issues/1329
https://github.com/py-pdf/pypdf/pull/1331
Fixed by: https://github.com/py-pdf/pypdf/commit/e6531a25325e7e0174b6a1ba03b57320b5227f6b (2.10.6)