Squid contains vulnerabilities in the the code handling NTLM (NT Lan
Manager), Gopher to HTML, ACLs and WCCP (Web Cache Communication Protocol)
which could lead to ACL bypass, denial of service and arbitrary code
execution.
Background
Squid is a full-featured Web proxy cache designed to run on Unix
systems. It supports proxying and caching of HTTP, FTP, and other URLs,
as well as SSL support, cache hierarchies, transparent caching, access
control lists and many other features.
Squid contains a vulnerability in the gopherToHTML function
(CAN-2005-0094) and incorrectly checks the 'number of caches' field
when parsing WCCP_I_SEE_YOU messages (CAN-2005-0095). Furthermore the
NTLM code contains two errors. One is a memory leak in the
fakeauth_auth helper (CAN-2005-0096) and the other is a NULL pointer
dereferencing error (CAN-2005-0097). Finally Squid also contains an
error in the ACL parsing code (CAN-2005-0194).
Impact
With the WCCP issue an attacker could cause denial of service by
sending a specially crafted UDP packet. With the Gopher issue an
attacker might be able to execute arbitrary code by enticing a user to
connect to a malicious Gopher server. The NTLM issues could lead to
denial of service by memory consumption or by crashing Squid. The ACL
issue could lead to ACL bypass.
Workaround
There is no known workaround at this time.
Resolution
All Squid users should upgrade to the latest version:
Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.