Secunia

Some vulnerabilities and a weakness have been reported in Tor, which can be exploited by malicious people to spoof log entries, disclose certain sensitive information, and cause a DoS (Denial of Service).

1) Input strings received from the network isn't properly sanitised before being displayed. This can potentially be exploited to spoof log entries via certain non-printable characters.

2) An unspecified error in the directory server can be exploited to cause a DoS.

3) Some integer overflow errors exists when adding elements to smartlists. This can potentially be exploited to cause a buffer overflow via malicious large inputs.

4) An error in which internal circuits are picked based on the circuits having useful exit nodes, can potentially reveal certain information via statistical attacks.

The vulnerabilities and weakness have been reported in versions prior to 0.1.1.20.

Note: Several other issues, which may be security related, have also been fixed.

Solution
Update to version 0.1.1.20.
Further details available in Customer Area

Provided and/or discovered by
1-3) Reported by vendor.
4) Lasse Overlier

Changelog
Further details available in Customer Area

Original Advisory
http://tor.eff.org/cvs/tor/ChangeLog

Deep Links
Links available in Customer Area