miniserv.pl in the webmin package does not properly handle metacharacters, such as line feeds and carriage returns, in Base64-encoded strings used in Basic authentication. This vulnerability allows remote attackers to spoof a session ID, and thereby gain root privileges.
For the stable distribution (woody) this problem has been fixed in version 0.94-7woody1.
The old stable distribution (potato) does not contain a webmin package.
For the unstable distribution (sid) this problem is fixed in version 1.070-1.
We recommend that you update your webmin package.