The rfc1738_do_escape function in ftp.c for Squid 2.5 STABLE11 and earlier allows remote FTP servers to cause a denial of service (segmentation fault) via certain "odd" responses.
store.c in Squid 2.5.STABLE10 and earlier allows remote attackers to cause a denial of service (crash) via certain aborted requests that trigger an assert error related to STORE_PENDING.
The sslConnectTimeout function in ssl.c for Squid 2.5.STABLE10 and earlier allows remote attackers to cause a denial of service (segmentation fault) via certain crafted requests.
The httpProcessReplyHeader function in http.c for Squid 2.5-STABLE7 and earlier does not properly set the debug context when it is handling "oversized" HTTP reply headers, which might allow remote attackers to poison the cache or bypass access controls based on header size.
Squid 2.5.STABLE8 and earlier allows remote attackers to cause a denial of service (crash) via certain DNS responses regarding (1) Fully Qualified Domain Names (FQDN) in fqdncache.c or (2) IP addresses in ipcache.c, which trigger an assertion failure.
Squid 2.5.STABLE9 and earlier does not trigger a fatal error when it identifies missing or invalid ACLs in the http_access configuration, which could lead to less restrictive ACLs than intended by the administrator.
Squid 2.5.STABLE7 and earlier allows remote attackers to cause a denial of service (segmentation fault) by aborting the connection during a (1) PUT or (2) POST request, which causes Squid to access previously freed memory.
Race condition in Squid 2.5.STABLE7 to 2.5.STABLE9, when using the Netscape Set-Cookie recommendations for handling cookies in caches, may cause Set-Cookie headers to be sent to other users, which allows attackers to steal the related cookies.
Squid 2.5 up to 2.5.STABLE7 allows remote attackers to poison the cache or conduct certain attacks via headers that do not follow the HTTP specification, including (1) multiple Content-Length headers, (2) carriage return (CR) characters that are not part of a CRLF pair, and (3) header names containing whitespace characters.