Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

9/26/2018
07:00 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
50%
50%

Critical Linux Kernel Flaw Gives Root Access to Attackers

All versions of Red Hat Enterprise Linux, CentOS vulnerable to 'Mutagen Astronomy' flaw, according to Qualys.

Multiple Linux distributions including all current versions of Red Hat Enterprise Linux and CentOS contain a newly discovered bug that gives attackers a way to obtain full root access on vulnerable systems.

The integer overflow flaw (CVE-2018-14634)exists in a critical Linux kernel function for memory management and allows attackers with unprivileged local access to a system to escalate their privileges. Researchers from security vendor Qualys discovered the issue and have developed a proof of concept exploit.

A patch for the flaw, which Qualys has dubbed "Mutagen Astronomy," is available, and most Linux distributions have already "backported" the patch for older versions of their kernels. But Red Hat Linux Enterprise, CentOS, and the Debian 8, or the "oldstable" version, are yet not patched, Qualys said in a security advisory this week.

In a statement, Red Hat said the issue impacts Red Hat Enterprise Linux 6, 7, and Red Hat Enterprise MRG 2. But versions of the Linux kernel shipped with Red Hat Linux 5 are not impacted, and systems with less than 32GB of memory are also very unlikely to be impacted by the vulnerability, "as they do not have a large enough address space to exploit this flaw," Red Hat said.

The vulnerability has been assigned a CVSS base score of 7.8, but Red Hat has assessed it as having high impact on confidentiality, integrity, and availability.  The vendor described the vulnerability as being exploitable with no user-interaction needed and involving low attack complexity.

Anagram

Jimmy Graham, director of product management and vulnerability management at Qualys, says the name "Mutagen Astronomy" is an anagram of "Too Many Arguments," which is the fundamental vulnerability being exploited.

The flaw is another reminder of the importance of the need for layered defenses, he says. Often attackers who exploit a remote vulnerability—such as a Web-application exploit, for instance—only gain unprivileged access on the vulnerable system.

So cybercriminals typically combine the use of lower-severity flaws with more severe ones like the Mutagen Astronomy flaw to create a very functional attack, Graham explains. "This type of vulnerability is often used in conjunction with other kinds of attacks," he says. "If an attacker has an existing foothold on a system but is unable to escalate to root, they may utilize a vulnerability like this to fully compromise the system."

That is why proper vulnerability and patch management is crucial, and should not be limited only to remediation of "critical" vulnerabilities, he adds.

Linux developer Kees Cook developed the patch for the flaw based on previous work by grsecurity, and most Linux distrbutions have backported it to their long-term-supported kernels. A backported patch is a patch that has been developed for the current mainline Linux kernel but can be applied to older, or long-term-supported (LTS) kernels, Graham says.

It's up to each Linux provider to decide if a patch is important enough for them to backport, and whether there's a likelihood of the patch harming the stability of their older LTS kernels.

"In this particular case, most distributions backported this patch, but Red Hat Enterprise Linux and CentOS did not," Graham says. All versions of these distributions are affected - even in their default and minimal installations, he notes.

Red Hat's advisory includes advice on how organizations can mitigate the vulnerability. The company will address the issue in updates for Red Hat Enterprise Linux 6, 7, and other affected versions.

Related Content:

 

Black Hat Europe returns to London Dec 3-6 2018  with hands-on technical Trainings, cutting-edge Briefings, Arsenal open-source tool demonstrations, top-tier security solutions and service providers in the Business Hall. Click for information on the conference and to register.

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
News
US Formally Attributes SolarWinds Attack to Russian Intelligence Agency
Jai Vijayan, Contributing Writer,  4/15/2021
News
Dependency Problems Increase for Open Source Components
Robert Lemos, Contributing Writer,  4/14/2021
News
FBI Operation Remotely Removes Web Shells From Exchange Servers
Kelly Sheridan, Staff Editor, Dark Reading,  4/14/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
2021 Top Enterprise IT Trends
We've identified the key trends that are poised to impact the IT landscape in 2021. Find out why they're important and how they will affect you today!
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-20527
PUBLISHED: 2021-04-19
IBM Resilient SOAR V38.0 could allow a privileged user to create create malicious scripts that could be executed as another user. IBM X-Force ID: 198759.
CVE-2021-27028
PUBLISHED: 2021-04-19
A Memory Corruption Vulnerability in Autodesk FBX Review version 1.4.0 may lead to remote code execution through maliciously crafted DLL files.
CVE-2021-27029
PUBLISHED: 2021-04-19
The user may be tricked into opening a malicious FBX file which may exploit a Null Pointer Dereference vulnerability in FBX's Review causing the application to crash leading to a denial of service.
CVE-2021-27030
PUBLISHED: 2021-04-19
A user may be tricked into opening a malicious FBX file which may exploit a Directory Traversal Remote Code Execution vulnerability in FBX’s Review causing it to run arbitrary code on the system.
CVE-2021-27031
PUBLISHED: 2021-04-19
A user may be tricked into opening a malicious FBX file which may exploit a use-after-free vulnerability in FBX's Review causing the application to reference a memory location controlled by an unauthorized third party, thereby running arbitrary code on the system.