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This is called Dirty COW, is dirty cattle vulnerability exists in the Linux kernel has been up to nine years, also said the 2007 release of the Linux kernel version existed vulnerability. Linux kernel team has conducted a repair.

Vulnerability ID:

CVE-2016-5195

Vulnerability name:

Dirty COW

Sphere of influence

Linux kernel >= 2.6.22

Vulnerability Overview:
Specifically, the Linux kernel’s memory subsystem generates race conditions when dealing with copy-on-write (COW). A malicious user could exploit this vulnerability to gain high-level access to read-only memory-mapped writes. (A race condition was found in the way the Linux kernel’s memory subsystem handled the copy-on-write (COW) breakage of private read-only memory mappings.)

Race conditions, which are exceptions to the order in which tasks are executed, can lead to application crashes, or allow an attacker to take advantage of further code execution. With this vulnerability, an attacker can raise privileges on their target system and may even gain root privileges.

According to the official release of the patch information, the problem can be traced back to the 2007 release of the Linux kernel. Now there is no evidence that after 2007 whether there is a hacker exploited this vulnerability. But security expert Phil Oester said he found an attacker to use the vulnerability to deploy the attack, and Red Hat informed of the recent attacks.

How to fix

Greg Kroah-Hartman, who maintains Linux kernel maintenance, fixes the maintenance update for the Linux 4.8, 4.7 and 4.4 LTS kernel families (updated with Linux kernel 4.8.3, 4.7.9, and 4.4.26 LTS) to fix the vulnerability. The newer versions are now available in the GNU / Linux distribution libraries, including Arch Linux (in beta), Solus, and all supported versions of Ubuntu. Debian developers also announced a stable version of the day before yesterday, Debian GNU / Linux 8 “Jessei” series kernel important update – this update fixes a total of four Linux kernel security vulnerabilities, including dirty cattle.

The operating system vendors should immediately download the Linux kernel 4.8.3, Linux kernel 4.7.9 and Linux kernel 4.4.26 LTS, to provide users with a stable version of the channel update.