Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.

http.cc in Squid 3.x before 3.5.15 and 4.x before 4.0.7 proceeds with the storage of certain data after a response-parsing failure, which allows remote HTTP servers to cause a denial of service (assertion failure and daemon exit) via a malformed response.

The Edge Side Includes (ESI) parser in Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not check buffer limits during XML parsing, which allows remote HTTP servers to cause a denial of service (assertion failure and daemon exit) via a crafted XML document, related to esi/CustomParser.cc and esi/CustomParser.h.

Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not properly append data to String objects, which allows remote servers to cause a denial of service (assertion failure and daemon exit) via a long string, as demonstrated by a crafted HTTP Vary header.

Off-by-one error in the snmpHandleUdp function in snmp_core.cc in Squid 2.x and 3.x, when an SNMP port is configured, allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted UDP SNMP request, which triggers a heap-based buffer overflow.

Multiple memory leaks in tools/cachemgr.cc in cachemgr.cgi in Squid 2.x and 3.x before 3.1.22, 3.2.x before 3.2.4, and 3.3.x before 3.3.0.2 allow remote attackers to cause a denial of service (memory consumption) via (1) invalid Content-Length headers, (2) long POST requests, or (3) crafted authentication credentials.

The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service (daemon abort) via a DNS reply containing a CNAME record that references another CNAME record that contains an empty A record.

Buffer overflow in the gopherToHTML function in gopher.cc in the Gopher reply parser in Squid 3.0 before 3.0.STABLE26, 3.1 before 3.1.15, and 3.2 before 3.2.0.11 allows remote Gopher servers to cause a denial of service (memory corruption and daemon restart) or possibly have unspecified other impact via a long line in a response. NOTE: This issue exists because of a CVE-2005-0094 regression.

The string-comparison functions in String.cci in Squid 3.x before 3.1.8 and 3.2.x before 3.2.0.2 allow remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted request.