The WCCP message parsing code in Squid 2.5.STABLE7 and earlier allows remote attackers to cause a denial of service (crash) via malformed WCCP messages with source addresses that are spoofed to reference Squid's home router and invalid WCCP_I_SEE_YOU cache numbers.

Buffer overflow in the gopherToHTML function in the Gopher reply parser for Squid 2.5.STABLE7 and earlier allows remote malicious Gopher servers to cause a denial of service (crash) via crafted responses.

The NTLM component in Squid 2.5.STABLE7 and earlier allows remote attackers to cause a denial of service (crash) via a malformed NTLM type 3 message that triggers a NULL dereference.

Squid Web Proxy Cache 2.5 might allow remote attackers to obtain sensitive information via URLs containing invalid hostnames that cause DNS operations to fail, which results in references to previously used error messages.

The "%xx" URL decoding function in Squid 2.5STABLE4 and earlier allows remote attackers to bypass url_regex ACLs via a URL with a NULL ("%00") character, which causes Squid to use only a portion of the requested URL when comparing it against the access control lists.