NetHack, Slash'EM, Falcon's Eye: Local privilege escalation

Background

NetHack is the classic single player dungeon exploration game. Slash’EM and Falcon’s Eye are NetHack variants.

Description

NetHack, Slash’EM and Falcon’s Eye have been found to be incompatible with the system used for managing games on Gentoo Linux. As a result, they cannot be played securely on systems with multiple users.

Impact

A local user who is a member of group “games” may be able to modify the state data used by NetHack, Slash’EM or Falcon’s Eye to trigger the execution of arbitrary code with the privileges of other players. Additionally, the games may create save game files in a manner not suitable for use on Gentoo Linux, potentially allowing a local user to create or overwrite files with the permissions of other players.

Workaround

Do not add untrusted users to the “games” group.

Resolution

NetHack has been masked in Portage pending the resolution of these issues. Vulnerable NetHack users are advised to uninstall the package until further notice.

 # emerge --ask --verbose --unmerge "games-roguelike/nethack"

Slash’EM has been masked in Portage pending the resolution of these issues. Vulnerable Slash’EM users are advised to uninstall the package until further notice.

 # emerge --ask --verbose --unmerge "games-roguelike/slashem"

Falcon’s Eye has been masked in Portage pending the resolution of these issues. Vulnerable Falcon’s Eye users are advised to uninstall the package until further notice.

 # emerge --ask --verbose --unmerge "games-roguelike/falconseye"