Squid ICP Traffic Handling Vulnerabilities
2026-03-26
Squid versions prior to 7.5 contain a heap use-after-free vulnerability (CWE-416) in ICP (Internet Cache Protocol) traffic handling that enables remote attackers to reliably trigger denial of service against affected proxy services. The vulnerability affects any Squid deployment with ICP support explicitly enabled via non-zero icp_port configuration, and cannot be mitigated through access control rules alone. A patch is available in version 7.5, and the vulnerability has been confirmed across multiple Debian releases and SUSE distributions.
Squid proxy versions prior to 7.5 contain use-after-free and premature resource release vulnerabilities in ICP (Internet Cache Protocol) traffic handling that enable reliable, repeatable denial of service attacks. Remote attackers can exploit these memory safety bugs to crash the Squid service by sending specially crafted ICP packets, affecting deployments that have explicitly enabled ICP support via non-zero icp_port configuration. While no CVSS score or EPSS value is currently published, the vulnerability is confirmed by vendor advisory and includes a public patch commit, indicating moderate to high real-world risk for affected deployments.
Squid prior to version 7.5 contains an out-of-bounds read vulnerability in ICP (Internet Cache Protocol) traffic handling due to improper input validation, classified as CWE-125. Remote attackers can exploit this to leak small amounts of process memory potentially containing sensitive information by sending malformed ICP requests to deployments with explicitly enabled ICP support (non-zero icp_port configuration). The vulnerability affects all versions of Squid before 7.5, and while no CVSS score or EPSS data is currently available, the information disclosure impact and remote attack vector indicate moderate to significant risk for affected deployments.