USN-59-1: mailman vulnerabilities

11 January 2005

mailman vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 4.10

Software Description


Florian Weimer discovered a cross-site scripting vulnerability in mailman’s automatically generated error messages. An attacker could craft an URL containing JavaScript (or other content embedded into HTML) which triggered a mailman error page. When an unsuspecting user followed this URL, the malicious content was copied unmodified to the error page and executed in the context of this page.

Juha-Matti Tapio discovered an information disclosure in the private rosters management. Everybody could check whether a specified email address was subscribed to a private mailing list by looking at the error message. This bug was Ubuntu/Debian specific.

Important note:

There is currently another known vulnerability: when an user subscribes to a mailing list without choosing a password, mailman automatically generates one. However, there are only about 5 million different possible passwords which allows brute force attacks.

A different password generation algorithm already exists, but is currently too immature to be put into a stable release security update. Therefore it is advisable to always explicitly choose a password for subscriptions, at least until this gets fixed in Warty Warthog.

See for details.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 4.10

To update your system, please follow these instructions: