GHSA-f4w8-cv6p-x6r5

Pillow Denial of Service by Uncontrolled Resource Consumption

At a glance

Published: 2021-03-18
Updated: 2025-08-15
CVE: CVE-2021-27921
Aliases: BIT-pillow-2021-27921, PYSEC-2021-40
CVSS_V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS_V4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Description

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 a BLP container, and thus an attempted memory allocation can be very large.

Affected packages

Package	Versions
PyPI · pillow	introduced 0, fixed 8.1.2

References

https://nvd.nist.gov/vuln/detail/CVE-2021-27921 ADVISORY
https://github.com/python-pillow/Pillow/commit/756fff33128a0b643d10518a26ad04b726dd8973 WEB
https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-40.yaml WEB
https://github.com/python-pillow/Pillow PACKAGE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ WEB
https://pillow.readthedocs.io/en/stable/releasenotes/8.1.1.html WEB
https://pillow.readthedocs.io/en/stable/releasenotes/8.1.2.html WEB
https://security.gentoo.org/glsa/202107-33 WEB

Sources

Source	Licence
OSV.dev	CC-BY 4.0 — GitHub Advisory Database