The "cache update reply processing" functionality in Squid 2.x before 2.6.STABLE17 and Squid 3.0 allows remote attackers to cause a denial of service (crash) via unknown vectors related to HTTP headers and an Array memory leak during requests for cached objects.

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.