MLDonkey: Privilege escalation — GLSA 200710-25

The Gentoo MLDonkey ebuild adds a user to the system with a valid login shell and no password.

Affected Packages

net-p2p/mldonkey on all architectures
Affected versions < 2.9.0-r3
Unaffected versions >= 2.9.0-r3

Background

MLDonkey is a peer-to-peer filesharing client that connects to several different peer-to-peer networks, including Overnet and BitTorrent.

Description

The Gentoo MLDonkey ebuild adds a user to the system named "p2p" so that the MLDonkey service can run under a user with low privileges. With older Portage versions this user is created with a valid login shell and no password.

Impact

A remote attacker could log into a vulnerable system as the p2p user. This would require an installed login service that permitted empty passwords, such as SSH configured with the "PermitEmptyPasswords yes" option, a local login console, or a telnet server.

Workaround

See Resolution.

Resolution

Change the p2p user's shell to disallow login. For example, as root run the following command:

 # usermod -s /bin/false p2p

NOTE: updating to the current MLDonkey ebuild will not remove this vulnerability, it must be fixed manually. The updated ebuild is to prevent this problem from occurring in the future.

References

Release Date
October 24, 2007

Latest Revision
November 07, 2007: 02

Severity
high

Exploitable
remote

Bugzilla entries