Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption) because the reported size of a contained image is not properly checked for an ICO container, and thus an attempted memory allocation can be very large.
References:- https://nvd.nist.gov/vuln/detail/CVE-2021-27923
- https://security.gentoo.org/glsa/202107-33
- https://github.com/python-pillow/Pillow/commit/756fff33128a0b643d10518a26ad04b726dd8973
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ
- https://github.com/advisories/GHSA-95q3-8gr9-gm8w
- https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-42.yaml
- https://pillow.readthedocs.io/en/stable/releasenotes/8.1.2.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ
- https://pillow.readthedocs.io/en/stable/releasenotes/8.1.1.html