CVE-2023-49285

Deeper analysis

Squid, a widely used caching proxy supporting HTTP, HTTPS, FTP and related protocols, contains a buffer overread vulnerability in its HTTP message processing code. The flaw, tracked as CVE-2023-49285 and assigned CWE-126 and CWE-125, allows an attacker to trigger a denial of service by supplying specially crafted input that causes Squid to read beyond allocated buffer boundaries. The issue affects multiple maintained release lines prior to the 6.5 release and carries a CVSS 3.1 base score of 8.6 reflecting network attack vector, low complexity, and high availability impact with no required privileges or user interaction.

An unauthenticated remote attacker can send malicious HTTP messages directly to an exposed Squid instance, causing the proxy to crash or become unresponsive. Because the vulnerability resides in core message parsing, the attack can be mounted against any deployment that accepts untrusted client or server traffic, including forward and reverse proxy configurations.

Official advisories and patches published by the Squid project state that the bug is resolved in version 6.5 and provide back-ported fixes for the 5.x series via the referenced SQUID-2023_7 patches and corresponding Git commits. No workarounds are documented, and administrators are advised to upgrade immediately. The associated EPSS score has remained low and stable near 0.096, indicating limited observed exploitation interest to date.