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Tor: Multiple vulnerabilities


1.  Gentoo Linux Security Advisory

Version Information

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 < >= All supported architectures

Related bugreports: #250018, #256078, #258833


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

2.  Impact Information


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


  • 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).


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


There is no known workaround at this time.


All Tor users should upgrade to the latest version:

Code Listing 3.1: Resolution

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

4.  References


Page updated April 08, 2009

Summary: This is a Gentoo Linux Security Advisory

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