Overly broad permissions can turn one compromised account into a much larger security problem. Learn how to reduce unnecessary access, review privileges, and apply least privilege across modern Linux systems. Review Linux Privileges×

Alerts This Week
Warning Icon 1 461
Alerts This Week
Warning Icon 1 461

CentOS 7.6 CESA-2018:3123-01 High: Kernel Security Bypass

red hat
Calendar Grey April 18, 2017
Scroller Redhat
The security notice from Red Hat regarding the kernel upgrade highlights a critical resolution pertaining to a vulnerability that could lead to privilege escalation.
An update for kernel is now available for Red Hat Enterprise Linux 6.4 Advanced Update Support

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Summary

The kernel packages contain the Linux kernel, the core of any Linux operating system.
Security Fix(es):
* A race condition flaw was found in the N_HLDC Linux kernel driver when accessing n_hdlc.tbuf list that can lead to double free. A local, unprivileged user able to set the HDLC line discipline on the tty device could use this flaw to increase their privileges on the system. (CVE-2017-2636, Important)
Red Hat would like to thank Alexander Popov for reporting this issue.

Topics%20covered

Topics Covered

security advisory Red Hat privilege escalation critical threat kernel important fix

References

https://access.redhat.com/security/cve/CVE-2017-2636 https://access.redhat.com/security/updates/classification#important

Package List

Red Hat Enterprise Linux Server AUS (v. 6.4):
Source: kernel-2.6.32-358.78.1.el6.src.rpm
noarch: kernel-doc-2.6.32-358.78.1.el6.noarch.rpm kernel-firmware-2.6.32-358.78.1.el6.noarch.rpm
x86_64: kernel-2.6.32-358.78.1.el6.x86_64.rpm kernel-debug-2.6.32-358.78.1.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm kernel-debug-devel-2.6.32-358.78.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-358.78.1.el6.x86_64.rpm kernel-devel-2.6.32-358.78.1.el6.x86_64.rpm kernel-headers-2.6.32-358.78.1.el6.x86_64.rpm perf-2.6.32-358.78.1.el6.x86_64.rpm perf-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm
Red Hat Enterprise Linux Server Optional AUS (v. 6.4):
Source: kernel-2.6.32-358.78.1.el6.src.rpm
x86_64: kernel-debug-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-358.78.1.el6.x86_64.rpm perf-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm python-perf-2.6.32-358.78.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-358.78.1.el6.x86_64.rpm
These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from https://access.redhat.com/security/team/key


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2017:0986-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2017:0986
Issue date: 2017-04-18

Topic

An update for kernel is now available for Red Hat Enterprise Linux 6.4Advanced Update Support.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory Red Hat privilege escalation critical threat kernel important fix

Relevant Releases Architectures

Red Hat Enterprise Linux Server AUS (v. 6.4) - noarch, x86_64

Red Hat Enterprise Linux Server Optional AUS (v. 6.4) - x86_64

Bugs Fixed

1428319 - CVE-2017-2636 kernel: Race condition access to n_hdlc.tbuf causes double free in n_hdlc_release()

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.