CVE-2018-1172: Squid-Cache Squid

Medium severity, CVSS 5.9. EPSS: 8.3% chance of exploitation in the next 30 days.

This vulnerability allows remote attackers to deny service on vulnerable installations of The Squid Software Foundation Squid 3.5.27-20180318. Authentication is not required to exploit this vulnerability. The specific flaw exists within ClientRequestContext::sslBumpAccessCheck(). A crafted request can trigger the dereference of a null pointer. An attacker can leverage this vulnerability to create a denial-of-service condition to users of the system. Was ZDI-CAN-6088.

Affected products

Published 2018-05-16. Last modified 2026-06-17.