Public Date:
1536939: CVE-2018-1000024 squid: Incorrect pointer handling when processing ESI Responses can lead to denial of service

The MITRE CVE dictionary describes this issue as:

The Squid Software Foundation Squid HTTP Caching Proxy version 3.0 to 3.5.27, 4.0 to 4.0.22 contains a Incorrect Pointer Handling vulnerability in ESI Response Processing that can result in Denial of Service for all clients using the proxy.. This attack appear to be exploitable via Remote server delivers an HTTP response payload containing valid but unusual ESI syntax.. This vulnerability appears to have been fixed in 4.0.23 and later.

Find out more about CVE-2018-1000024 from the MITRE CVE dictionary dictionary and NIST NVD.

CVSS v3 metrics

NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.

CVSS3 Base Score 7.4
CVSS3 Base Metrics CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Changed
Confidentiality None
Integrity Impact None
Availability Impact High

Affected Packages State

Platform Package State
Red Hat Enterprise Linux 8 squid Not affected
Red Hat Enterprise Linux 7 squid Will not fix
Red Hat Enterprise Linux 6 squid34 Will not fix
Red Hat Enterprise Linux 6 squid Will not fix
Red Hat Enterprise Linux 5 squid Not affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.


A workaround for this issue is to not use the internal ESI parser, which can be achieved by adding either the "esi_parser expat" or "esi_parser libxml2" configuration directive to the squid configuration file (for example /etc/squid/squid.conf).

Last Modified

CVE description copyright © 2017, The MITRE Corporation