Tor: Multiple vulnerabilities

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Updated April 08, 2009

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200904-11 / tor
Release Date	April 08, 2009
Latest Revision	April 08, 2009: 01
Impact	high
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-misc/tor	< 0.2.0.34	>= 0.2.0.34	All supported architectures

Related bugreports: #250018, #256078, #258833

Synopsis

Multiple vulnerabilities in Tor might allow for heap corruption, Denial of Service, escalation of privileges and information disclosure.

2. Impact Information

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.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Tor users should upgrade to the latest version:

Code Listing 3.1: Resolution

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

4. References