CVE-2023-49288

HIGH

Squid 3.5-5.9 - Use-After-Free via Collapsed Forwarding

Title source: llm
STIX 2.1

Description

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Affected versions of squid are subject to a a Use-After-Free bug which can lead to a Denial of Service attack via collapsed forwarding. All versions of Squid from 3.5 up to and including 5.9 configured with "collapsed_forwarding on" are vulnerable. Configurations with "collapsed_forwarding off" or without a "collapsed_forwarding" directive are not vulnerable. This bug is fixed by Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should remove all collapsed_forwarding lines from their squid.conf.

References (4)

Core 4

Scores

CVSS v3 8.6
EPSS 0.0478
EPSS Percentile 90.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-416
Status published
Products (1)
squid-cache/squid 3.5 - 5.9
Published Dec 04, 2023
Tracked Since Feb 18, 2026