Use After Free in Squid-Cache Squid

CVE-2023-49288

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.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.048 (91.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 91.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-49288: held from 0.048 to 0.048.

EPSS over last 30 days · oldest: 0.048 · newest: 0.048 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-49288?
CVE-2023-49288 is a high-severity vulnerability in Squid-Cache Squid, classified under Use After Free. CVSS score: 8.6/10. Published 2023-12-04.
How severe is CVE-2023-49288?
High severity. CVSS v3 base score is 8.6 out of 10.
Is CVE-2023-49288 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.