Easy-to-exploit rooting flaw puts Linux computers at risk

The flaw allows attackers with limited access to Linux computers to gain root privileges

The maintainers of Linux distributions are rushing to patch a privilege escalation vulnerability that's already being exploited in the wild and poses a serious risk to servers, desktops and other devices that run the OS.

The vulnerability, tracked as CVE-2016-5195, has existed in the Linux kernel for the past nine years. This means that many kernel versions that are used in a variety of computers, servers, routers, embedded devices and hardware appliances are affected.

The Red Hat security team describes the flaw as a "race" condition, "in the way the Linux kernel's memory subsystem handles the copy-on-write (COW) breakage of private read-only memory mappings." This allows an attacker who gains access to a limited user account to obtain root privileges and therefore take complete control over the system.

The vulnerability was fixed this week by the Linux kernel developers and patches for Linux distributions, including Red Hat, Debian, Ubuntu, Gentoo and Suse, have been released or are in the process of being released.

The vulnerability, which has been dubbed Dirty COW by the security community, was discovered by security researcher Phil Oester when it was reportedly used in an attack against one of his servers. This suggests that attackers have known about the vulnerability and have exploited it in the wild for some time.

Since this is a local privilege escalation flaw that cannot be directly exploited by remote attackers, it is only rated as high severity and not critical. To take advantage of it attackers need to first obtain limited access to a server in some other way, such as through another vulnerability.

Shared web hosting companies are at higher risk because some of them offer local shell access to customers, so a malicious user could take over their servers. Vulnerabilities in web applications that allows attackers to create and execute files on servers can also be exploited to gain an initial foothold from where attackers can then escalate their privileges to root.

Linux server administrators are advised to immediately install the patch for this vulnerability. If a patch is not yet available for their systems, they should consider applying a mitigation developed by the Red Hat security team.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?