Updated 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. (CVE-2007-5964)
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.