CVE-2013-1858: High severity linux kernel vulnerability
Linux kernels which support unprivileged user namespaces (CLONENEWUSER) and at the same time allow sharing file system information (CLONEFS) between parent process and its newly clone(2)d child process in the new user namespace, are vulnerable to a privilege escalation flaw as presented by Sebastian Krahmer in his chroot exploit [1].
[1] http://stealth.openwall.net/xSports/clown-newuser.c
An unprivileged local user could use this flaw to gain root privileges on a system.
Upstream fix: ------------- -> https://git.kernel.org/linus/e66eded8309ebf679d3d3c1f5820d1f2ca332c71
Reference: ---------- -> http://www.openwall.com/lists/oss-security/2013/03/13/8
Other sources
The clone system-call implementation in the Linux kernel before 3.8.3 does not properly handle a combination of the CLONENEWUSER and CLONEFS flags, which allows local users to gain privileges by calling chroot and leveraging the sharing of the / directory between a parent process and a child process.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2013-1858?
The severity of CVE-2013-1858 is considered high due to its potential for privilege escalation.
How do I fix CVE-2013-1858?
To fix CVE-2013-1858, you should upgrade your Linux kernel to versions above 3.8.2 or apply relevant patches.
Which systems are affected by CVE-2013-1858?
CVE-2013-1858 affects Linux kernels supporting unprivileged user namespaces and versions up to 3.8.2.
What exploits exist for CVE-2013-1858?
Exploits for CVE-2013-1858 can allow an unprivileged user to gain elevated rights within a user namespace.
How does CVE-2013-1858 work?
CVE-2013-1858 leverages the sharing of file system information between a parent and a cloned child process in unprivileged user namespaces.