mount in util-linux 2.19 and earlier does not remove the /etc/mtab.tmp file after a failed attempt to add a mount entry, which allows local users to trigger corruption of the /etc/mtab file via multiple invocations.

References

• https://nvd.nist.gov/vuln/detail/CVE-2011-1676
• https://bugzilla.redhat.com/show_bug.cgi?id=688980
• https://exchange.xforce.ibmcloud.com/vulnerabilities/66704
• http://openwall.com/lists/oss-security/2011/03/04/10
• http://openwall.com/lists/oss-security/2011/03/04/11
• http://openwall.com/lists/oss-security/2011/03/04/12
• http://openwall.com/lists/oss-security/2011/03/04/9
• http://openwall.com/lists/oss-security/2011/03/05/3
• http://openwall.com/lists/oss-security/2011/03/05/7
• http://openwall.com/lists/oss-security/2011/03/07/9
• http://openwall.com/lists/oss-security/2011/03/14/16
• http://openwall.com/lists/oss-security/2011/03/14/5
• http://openwall.com/lists/oss-security/2011/03/14/7
• http://openwall.com/lists/oss-security/2011/03/15/6
• http://openwall.com/lists/oss-security/2011/03/22/4
• http://openwall.com/lists/oss-security/2011/03/22/6
• http://openwall.com/lists/oss-security/2011/03/31/3
• http://openwall.com/lists/oss-security/2011/03/31/4
• http://openwall.com/lists/oss-security/2011/04/01/2