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 clientAbortBody function in client_side.c in Squid Web Proxy Cache before 2.6 STABLE6 allows remote attackers to cause a denial of service (segmentation fault) via unspecified vectors that trigger a null dereference. NOTE: in a followup advisory, a researcher claimed that the issue was a buffer overflow that was not fixed in STABLE6. However, the vendor's bug report clearly shows that the researcher later retracted this claim, because the tested product was actually STABLE5.

Squid Web Proxy Cache 2.3.STABLE5 allows remote attackers to bypass security controls and access arbitrary websites via "@@" sequences in a URL within Internet Explorer.

The (1) ntlm_fetch_string and (2) ntlm_get_string functions in Squid 2.5.6 and earlier, with NTLM authentication enabled, allow remote attackers to cause a denial of service (application crash) via an NTLMSSP packet that causes a negative value to be passed to memcpy.

Buffer overflow in the ntlm_check_auth (NTLM authentication) function for Squid Web Proxy Cache 2.5.x and 3.x, when compiled with NTLM handlers enabled, allows remote attackers to execute arbitrary code via a long password ("pass" variable).

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.

phpSquidPass before 0.2 uses an incomplete regular expression to find a matching username in its database, which allows remote authenticated attackers to effectively delete other usernames via a short username that matches the end of the targeted username.

Opera 6.0.3, when using Squid 2.4 for HTTPS proxying, does not properly handle when accepting a non-global certificate authority (CA) certificate from a site and establishing a subsequent HTTPS connection, which allows remote attackers to cause a denial of service (crash).