RHEL 4 : autofs5 (RHSA-2007:1129)
Medium Nessus Plugin ID 29693
SynopsisThe remote Red Hat host is missing a security update.
DescriptionUpdated Red Hat Enterprise Linux 4 Technology Preview autofs5 packages are now available to fix a security flaw.
This update has been rated as having important security impact by the Red Hat Security Response Team.
The autofs utility controls the operation of the automount daemon, which automatically mounts and unmounts file systems after a period of inactivity. The autofs version 5 package was made available as a technology preview in Red Hat Enterprise Linux version 4.6.
There was a security issue with the default installed configuration of autofs version 5 whereby the entry for the 'hosts' map did not specify the 'nosuid' mount option. A local user with control of a remote nfs server could create a setuid root executable within an exported filesystem on the remote nfs server that, if mounted using the default hosts map, would allow the user to gain root privileges.
Due to the fact that autofs version 5 always mounted hosts map entries suid by default, autofs has now been altered to always use the 'nosuid' option when mounting from the default hosts map. The 'suid' option must be explicitly given in the master map entry to revert to the old behavior. This change affects only the hosts map which corresponds to the /net entry in the default configuration.
Users are advised to upgrade to these updated autofs5 packages, which resolve this issue.
Red Hat would like to thank Josh Lange for reporting this issue.
SolutionUpdate the affected autofs5 package.