CVE Vulnerabilities

CVE-2021-27923

Uncontrolled Resource Consumption

Published: Mar 03, 2021 | Modified: Dec 06, 2021
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Ubuntu

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.

Weakness

The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affected Software

Name Vendor Start Version End Version
Pillow Python * *
Red Hat Enterprise Linux 8 RedHat python-pillow-0:5.1.1-16.el8 *
Red Hat Quay 3 RedHat quay/quay-rhel8:v3.6.0-62 *
Pillow Ubuntu bionic *
Pillow Ubuntu esm-infra/xenial *
Pillow Ubuntu focal *
Pillow Ubuntu groovy *
Pillow Ubuntu trusty *
Pillow Ubuntu upstream *
Pillow Ubuntu xenial *
Pillow-python2 Ubuntu groovy *
Python-imaging Ubuntu precise/esm *

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the software, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References