The MITRE CVE dictionary describes this issue as:
fusermount in fuse 2.8.5 and earlier does not perform a chdir to / before performing a mount or umount, which allows local users to unmount arbitrary directories via unspecified vectors.
Find out more about CVE-2011-0542 from the
MITRE CVE dictionary dictionary and
The Red Hat Security Response Team has rated this issue as having low security impact. On Red Hat Enterprise Linux 5 and 6, a user must be a member of the 'fuse' group in order to use FUSE. Due to the risks associated with fixing this bug on Red Hat Enterprise Linux 5, and because of the group restrictions in place, we currently have no plans to fix this flaw in Red Hat Enterprise Linux 5.