GLSA 200710-25: MLDonkey: Privilege escalation

http://security.gentoo.org/

Severity:	high
Title:	MLDonkey: Privilege escalation
Date:	10/24/2007
Bugs:	#189412
ID:	200710-25

Synopsis

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

Background

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

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
net-p2p/mldonkey	< 2.9.0-r3	>= 2.9.0-r3	All supported architectures

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

CVE-2007-5714

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200710-25.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.