CVE-2019-18677

An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because the appended characters do not properly interact with hostname length restrictions). Due to incorrect message processing, it can inappropriately redirect traffic to origins it should not be delivered to.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

As per upstream:

Remove append_domain configuration settings from squid.conf. The append_domain feature is redundant when /etc/resolv.conf is used to determine hostnames. However, please note that use of /etc/resolv.conf may require removal of dns_nameservers and other redundant DNS directives.