CVE-2023-50269
squid: denial of service in HTTP request parsing
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 14, 2023
Updated · November 21, 2025
Description
A flaw was found in Squid, which is susceptible to a Denial of Service (DoS) due to an Uncontrolled Recursion bug, specifically targeting HTTP Request parsing. Exploiting this issue involves a remote client initiating a DoS attack by sending an oversized X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This issue poses a threat to the stability and availability of the Squid service.
Statement
Squid configurations lacking the "follow_x_forwarded_for" setting are not susceptible to the vulnerability.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Remove all "follow_x_forwarded_for" lines from squid.conf.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-674 · Uncontrolled Recursion