A local privilege escalation vulnerability is found in the Linux kernel 2.6.22 or later. A flaw exists in the Linux kernel which contains a race condition in the way the copy-on-write mechanism is handled by the memory subsystem. A local attacker may leverage this vulnerability in the affected systems to gain root privileges.
Successful exploitation could lead to elevation of privilege or compromise of a vulnerable system.
The vulnerability is fixed in some of the Linux distributions. Linux system administrators should check with their product vendors to confirm if their Linux systems are affected and the availability of patches, and if so, upgrade to the fixed versions or follow the recommendations provided by the product vendors to mitigate the risk. Lists of affected Linux distribution and fixed version are available in the following URL:
Users of affected systems should follow the recommendations provided by the product vendor and take immediate actions to mitigate the risk.
https://www.kb.cert.org/vuls/id/243144
https://dirtycow.ninja/
https://www.hkcert.org/my_url/en/alert/16102401
https://www.us-cert.gov/ncas/current-activity/2016/10/21/Linux-Kernel-Vulnerability
https://access.redhat.com/security/cve/cve-2016-5195
https://security-tracker.debian.org/tracker/CVE-2016-5195
http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-5195.html
https://www.suse.com/security/cve/CVE-2016-5195.html
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.8.3
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.7.9
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.26
https://cwe.mitre.org/data/definitions/362.html
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5195