Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.

The FwdState::connectedToPeer method in FwdState.cc in Squid before 3.5.14 and 4.0.x before 4.0.6 does not properly handle SSL handshake errors when built with the --with-openssl option, which allows remote attackers to cause a denial of service (application crash) via a plaintext HTTP message.

Heap-based buffer overflow in the Icmp6::Recv function in icmp/Icmp6.cc in the pinger utility in Squid before 3.5.16 and 4.x before 4.0.8 allows remote servers to cause a denial of service (performance degradation or transition failures) or write sensitive information to log files via an ICMPv6 packet.

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.

http.cc in Squid 4.x before 4.0.7 relies on the HTTP status code 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.

Squid 3.4.4 through 3.4.11 and 3.5.0.1 through 3.5.1, when Digest authentication is used, allow remote authenticated users to retain access by leveraging a stale nonce, aka "Nonce replay vulnerability."

Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.