CVE-2011-4096

CVE-2011-4096 describes a memory management vulnerability in Squid versions prior to 3.1.16. Specifically, the idnsGrokReply function fails to properly free memory when processing a crafted DNS reply involving nested CNAME records and an empty A record. This flaw allows remote attackers to trigger a denial of service (daemon abort) in affected Squid installations. The vulnerability has a CVSS score of 5.0 (medium severity) with a vector of AV:N/AC:L/Au:N/C:N/I:N/A:P, indicating it can be exploited remotely with low complexity and no authentication, leading to a partial availability impact. Its FAUCET Risk Score is high at 98/100, and its EPSS score of 0.6249 suggests a higher-than-average probability of exploitation. Despite the elevated risk scores, there is no evidence of active exploitation (KEV: No) and no publicly available exploit code in Metasploit, Nuclei, or ExploitDB. However, the CVE has garnered significant community discussion with 10 mentions, indicating awareness and potential interest among security researchers.