GHSA-hjfx-8p6c-g7gx BIT-pillow-2021-28678 CVE-2021-28678 PYSEC-2021-94

Insufficient Verification of Data Authenticity in Pillow

Medium PyPI

Severity: 0.0 / 10; Medium · CVSS 4.0
Exploit chance (EPSS): 0.73%; Chance of exploitation in the next 30 days. Higher than 54.33% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-345 Insufficient Verification of Data Authenticity
Fix: 8.2.0; Upgrade pillow to this version or later

Description

An issue was discovered in Pillow before 8.2.0. For BLP data, BlpImagePlugin did not properly check that reads (after jumping to file offsets) returned data. This could lead to a DoS where the decoder could be run a large number of times on empty data.

Affected versions

PyPI

Package	Vulnerable	Fixed in
pillow	`>= 5.1.0, < 8.2.0`	`8.2.0`
pillow	`< 8.2.0`	`8.2.0`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

pillow PyPI → `8.2.0`

pip

pip install --upgrade "pillow>=8.2.0"

poetry

poetry add "pillow>=8.2.0"

uv

uv add "pillow>=8.2.0"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack vector: Local
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: Passive
Confidentiality (vulnerable system): None
Integrity (vulnerable system): None
Availability (vulnerable system): High
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

CVSS 3.1 5.5

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Attack vector: Local
Attack complexity: Low
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Weakness

CWE-345: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

References

Advisories

Packages

github.com/python-pillow/Pillow

Timeline

Jun 2, 2021 Published
Oct 14, 2024 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
PYSEC-2023-175 Pillow versions before v10.0.1 bundled libwebp binaries in wheels that are vulnerable to CVE-2023-5129 (previously CVE-2023-4863).	High Known exploited	Also affects pillow
GHSA-j7hp-h8jx-5ppr libwebp: OOB write in BuildHuffmanTable	High Known exploited	Also affects pillow
GHSA-78g4-xqwv-q3g8 Pillow: Bundled libopenjp2 2.5.4 in all wheels since 11.1.0 carries OSV-2025-219 heap-buffer-overflow write reachable from Image.open().load()	High	Also affects pillow
GHSA-654x-cwwv-5j9c Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT > 1	Medium	Also affects pillow
GHSA-xvh5-g6gv-559v Pillow: Memory disclosure and segfault in libtiff encoder via crafted TIFF tags	High	Also affects pillow
GHSA-g7cr-3p24-7wf7 Pillow: Heap buffer overflow writing JPEG comment after ICC profile fills buffer	High	Also affects pillow
GHSA-9v9v-9qvf-h2hj Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)	High	Also affects pillow
GHSA-g4qv-2jxx-769h Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time	Medium	Also affects pillow

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