CVE-2021-27923

python-pillow: Excessive memory allocation in ICO image reader

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Pillow before 8.1.1 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.

Pillow versiones anteriores a 8.1.1, permite a atacantes causar una denegación de servicio (consumo de la memoria) porque el tamaño reportado de una imagen contenida no es comprobado apropiadamente para un contenedor ICO y, por lo tanto, un intento de asignación de memoria puede ser muy grande

A flaw was found in python-pillow. Attackers can 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.

The python-pillow packages contain a Python image processing library that provides extensive file format support, an efficient internal representation, and powerful image-processing capabilities. Issues addressed include buffer over-read, buffer overflow, denial of service, and out of bounds read vulnerabilities.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-03-03 CVE Reserved
2021-03-03 CVE Published
2024-08-03 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation
CWE-400: Uncontrolled Resource Consumption

CAPEC

References (7)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ	2023-11-07
https://pillow.readthedocs.io/en/stable/releasenotes/8.1.1.html	2023-11-07
https://security.gentoo.org/glsa/202107-33	2023-11-07
https://access.redhat.com/security/cve/CVE-2021-27923	2021-11-09
https://bugzilla.redhat.com/show_bug.cgi?id=1935401	2021-11-09

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Python Search vendor "Python"		Pillow Search vendor "Python" for product "Pillow"				< 8.1.1 Search vendor "Python" for product "Pillow" and version " < 8.1.1"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				32 Search vendor "Fedoraproject" for product "Fedora" and version "32"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				33 Search vendor "Fedoraproject" for product "Fedora" and version "33"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				34 Search vendor "Fedoraproject" for product "Fedora" and version "34"		-		Affected