An issue was discovered in Squid before 4.10. It allows a crafted FTP server to trigger disclosure of sensitive information from heap memory, such as information associated with other users" sessions or non-Squid processes. An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing "+\ "-" or an uncommon shell whitespace character prefix to the length field-value. A flaw was found in squid. Due to incorrect data validation, a HTTP Request Smuggling attack against HTTP and HTTPS traffic is possible leading to cache poisoning. The highest threat from this vulnerability is to data confidentiality and integrity. A flaw was found in squid. Due to incorrect data validation, an HTTP Request Splitting attack against HTTP and HTTPS traffic is possible leading to cache poisoning. The highest threat from this vulnerability is to data confidentiality and integrity. Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply livelocking in peer_digest.cc mishandles EOF. An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted HTTP requests in unexpected ways to access server resources prohibited by earlier security filters. An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can cause a buffer overflow in a Squid instance acting as a reverse proxy