dns_internal.cc in Squid 3.1.6, when IPv6 DNS resolution is not enabled, accesses an invalid socket during an IPv4 TCP DNS query, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via vectors that trigger an IPv4 DNS response with the TC bit set.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.456
EPSS Ranking 97.5%