CVE-2014-5206: High severity linux kernel vulnerability
It was discovered that a privileged user in the user namespace with access to a bind mount can clear certain mount flags by calling "mount --bind -o remount,... ...".
Proposed patches:
https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=a6138db815df5ee542d848318e5dae681590fccd https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=07b645589dcda8b7a5249e096fece2a67556f0f4 https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=9566d6742852c527bf5af38af5cbb878dad75705 https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=db181ce011e3c033328608299cd6fac06ea50130
References: http://seclists.org/oss-sec/2014/q3/357
Other sources
The doremount function in fs/namespace.c in the Linux kernel through 3.16.1 does not maintain the MNTLOCKREADONLY bit across a remount of a bind mount, which allows local users to bypass an intended read-only restriction and defeat certain sandbox protection mechanisms via a "mount -o remount" command within a user namespace.
— MITRE
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2014-5206?
CVE-2014-5206 has a high severity rating due to the potential for a privileged user to clear mount flags, impacting system security.
How do I fix CVE-2014-5206?
To fix CVE-2014-5206, you should apply the patches provided by the Linux kernel maintainers or update to a non-vulnerable version of the kernel.
Which versions of the Linux kernel are affected by CVE-2014-5206?
CVE-2014-5206 affects multiple Linux kernel versions between 3.8 and 3.16.3.
Who can be impacted by CVE-2014-5206?
CVE-2014-5206 can be exploited by a privileged user within the user namespace, potentially compromising system integrity.
Is CVE-2014-5206 specifically related to Ubuntu Linux distributions?
Yes, CVE-2014-5206 affects specific versions of Ubuntu Linux, including 12.04 and 14.04.