CVE Vulnerabilities


Uncontrolled Resource Consumption

Published: Feb 04, 2024 | Modified: Jun 14, 2024
CVSS 3.x
CVSS 2.x

libexpat through 2.5.0 allows a denial of service (resource consumption) because many full reparsings are required in the case of a large token for which multiple buffer fills are needed.


The product 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
Libexpat Libexpat_project * 2.5.0 (including)
Red Hat Enterprise Linux 8 RedHat expat-0:2.2.5-11.el8_9.1 *
Red Hat Enterprise Linux 8 RedHat xmlrpc-c-0:1.51.0-9.el8_10 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat expat-0:2.2.5-8.el8_6.5 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat expat-0:2.2.5-11.el8_8.2 *
Red Hat Enterprise Linux 9 RedHat expat-0:2.5.0-1.el9_3.1 *
Red Hat Enterprise Linux 9 RedHat expat-0:2.5.0-1.el9_3.1 *
Red Hat Enterprise Linux 9.2 Extended Update Support RedHat expat-0:2.5.0-1.el9_2.1 *
Apache2 Ubuntu trusty *
Apr-util Ubuntu trusty *
Ayttm Ubuntu trusty *
Ayttm Ubuntu xenial *
Cableswig Ubuntu trusty *
Cableswig Ubuntu xenial *
Cadaver Ubuntu bionic *
Cadaver Ubuntu mantic *
Cadaver Ubuntu trusty *
Cadaver Ubuntu xenial *
Cmake Ubuntu trusty *
Coin3 Ubuntu bionic *
Coin3 Ubuntu trusty *
Coin3 Ubuntu xenial *
Expat Ubuntu bionic *
Expat Ubuntu devel *
Expat Ubuntu esm-infra-legacy/trusty *
Expat Ubuntu esm-infra/bionic *
Expat Ubuntu esm-infra/xenial *
Expat Ubuntu focal *
Expat Ubuntu jammy *
Expat Ubuntu mantic *
Expat Ubuntu noble *
Expat Ubuntu trusty *
Expat Ubuntu trusty/esm *
Expat Ubuntu upstream *
Expat Ubuntu xenial *
Firefox Ubuntu bionic *
Firefox Ubuntu trusty *
Firefox Ubuntu xenial *
Gdcm Ubuntu trusty *
Ghostscript Ubuntu trusty *
Insighttoolkit4 Ubuntu bionic *
Insighttoolkit4 Ubuntu trusty *
Insighttoolkit4 Ubuntu xenial *
Libxmltok Ubuntu bionic *
Libxmltok Ubuntu devel *
Libxmltok Ubuntu esm-apps/bionic *
Libxmltok Ubuntu esm-apps/focal *
Libxmltok Ubuntu esm-apps/jammy *
Libxmltok Ubuntu esm-apps/noble *
Libxmltok Ubuntu esm-apps/xenial *
Libxmltok Ubuntu focal *
Libxmltok Ubuntu jammy *
Libxmltok Ubuntu mantic *
Libxmltok Ubuntu noble *
Libxmltok Ubuntu trusty *
Libxmltok Ubuntu xenial *
Matanza Ubuntu bionic *
Matanza Ubuntu mantic *
Matanza Ubuntu trusty *
Matanza Ubuntu xenial *
Smart Ubuntu trusty *
Swish-e Ubuntu bionic *
Swish-e Ubuntu mantic *
Swish-e Ubuntu trusty *
Swish-e Ubuntu xenial *
Tdom Ubuntu bionic *
Tdom Ubuntu mantic *
Tdom Ubuntu trusty *
Tdom Ubuntu xenial *
Texlive-bin Ubuntu trusty *
Thunderbird Ubuntu bionic *
Thunderbird Ubuntu mantic *
Thunderbird Ubuntu trusty *
Thunderbird Ubuntu xenial *
Vnc4 Ubuntu bionic *
Vnc4 Ubuntu trusty *
Vnc4 Ubuntu xenial *
Vtk Ubuntu trusty *
Vtk Ubuntu xenial *
Wbxml2 Ubuntu bionic *
Wbxml2 Ubuntu mantic *
Wbxml2 Ubuntu trusty *
Wbxml2 Ubuntu xenial *
Xmlrpc-c Ubuntu bionic *
Xmlrpc-c Ubuntu mantic *
Xmlrpc-c Ubuntu trusty *
Xmlrpc-c Ubuntu xenial *

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 product, 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.