Tor: Multiple vulnerabilities

Background

Tor is an implementation of second generation Onion Routing, a connection-oriented anonymizing communication service.

Description

• Theo de Raadt reported that the application does not properly drop privileges to the primary groups of the user specified via the “User” configuration option (CVE-2008-5397).
• rovv reported that the “ClientDNSRejectInternalAddresses” configuration option is not always enforced (CVE-2008-5398).
• Ilja van Sprundel reported a heap-corruption vulnerability that might be remotely triggerable on some platforms (CVE-2009-0414).
• It has been reported that incomplete IPv4 addresses are treated as valid, violating the specification (CVE-2009-0939).
• Three unspecified vulnerabilities have also been reported (CVE-2009-0936, CVE-2009-0937, CVE-2009-0938).

Impact

A local attacker could escalate privileges by leveraging unintended supplementary group memberships of the Tor process. A remote attacker could exploit these vulnerabilities to cause a heap corruption with unknown impact and attack vectors, to cause a Denial of Service via CPU consuption or daemon crash, and to weaken anonymity provided by the service.

Workaround

There is no known workaround at this time.

Resolution

All Tor users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-misc/tor-0.2.0.34"