The addmntent function in the GNU C Library (aka glibc or libc6) 2.13 and earlier does not report an error status for failed attempts to write to the /etc/mtab file, which makes it easier for local users to trigger corruption of this file, as demonstrated by writes from a process with a small RLIMIT_FSIZE value, a different vulnerability than CVE-2010-0296.

The encode_name macro in misc/mntent_r.c in the GNU C Library (aka glibc or libc6) 2.11.1 and earlier, as used by ncpmount and mount.cifs, does not properly handle newline characters in mountpoint names, which allows local users to cause a denial of service (mtab corruption), or possibly modify mount options and gain privileges, via a crafted mount request.