tcptraceroute is a setuid-root program which drops root privileges after obtaining a file descriptor used for raw packet capture. However, it did not fully relinquish all privileges, and in the event of an exploitable vulnerability, root privileges could be regained.
No current exploit is known, but this safeguard is being repaired in order to provide a measure of containment in the event that an exploitable flaw should be discovered.
For the stable distribution (woody) this problem has been fixed in version 1.2-2.
The old stable distribution (potato) does not contain a tcptraceroute package.
For the unstable distribution (sid) this problem is fixed in version 1.4-4.
We recommend that you update your tcptraceroute package.
MD5 checksums of the listed files are available in the original advisory.