CVE-2020-15810

An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to
incorrect data validation, HTTP Request Smuggling attacks may succeed
against HTTP and HTTPS traffic. This leads to cache poisoning. This allows
any client, including browser scripts, to bypass local security and poison
the proxy cache and any downstream caches with content from an arbitrary
source. When configured for relaxed header parsing (the default), Squid
relays headers containing whitespace characters to upstream servers. When
this occurs as a prefix to a Content-Length header, the frame length
specified will be ignored by Squid (allowing for a conflicting length to be
used from another Content-Length header) but relayed upstream.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=968934&gt;