CVE-2023-50269highCWE-674

CVE-2023-50269: high-severity vulnerability in squid-cache squid

SQUID-2023:10 Denial of Service in HTTP Request parsing

Published · Updated

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33Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.6epss 58%
What the vendors declare (VEX)

Official vendor statements in CSAF/VEX format: whether their product is affected, already fixed, or ruled out — and why. These are the vendor's assertions, not Vexday's judgment.

Red HatVEX document ↗
Affected
1 product (4 components)
Red Hat Enterprise Linux 6
workaround: Remove all "follow_x_forwarded_for" lines from squid.conf.
Fixed
16 products (265 components)
Red Hat Enterprise Linux AppStream (v. 8) · Red Hat Enterprise Linux AppStream EUS (v.8.6) · Red Hat Enterprise Linux AppStream EUS (v.8.8) · Red Hat Enterprise Linux Server (v. 7) · Red Hat Enterprise Linux Server Optional (v. 7) · and others 11
fix ↗
In short

Squid proxy has a bug where specially crafted HTTP requests with large X-Forwarded-For headers can crash the server, making it unavailable. This happens when a specific feature (follow_x_forwarded_for) is enabled.

Technical detail

An uncontrolled recursion vulnerability (CWE-674) in Squid's HTTP request parsing allows remote attackers to trigger a Denial of Service by sending oversized X-Forwarded-For headers when follow_x_forwarded_for is configured. The attack vector is network-based and requires no authentication; exploitation causes the proxy to exhaust resources and become unavailable.

Summary generated and translated by AI from the official description.
Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
squid-cache · squid
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