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 1 544
Alerts This Week
Warning Icon 1 544

Ubuntu 15.10: USN-2852-1 Critical: Kernel Namespace Access Threat

ubuntu
Calendar Grey December 20, 2015
Scroller Ubuntu
Ubuntu Security Alert USN-2853-1 highlights a critical kernel flaw enabling unauthorized access to namespaces. Swift action is necessary.
The system could be made to provide access outside of namespace sandbox.

Summary

The system could be made to provide access outside of namespace sandbox.

Software Description:

- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

Jann Horn discovered a ptrace issue with user namespaces in the Linux

kernel. The namespace owner could potentially exploit this flaw by ptracing

a root owned process entering the user namespace to elevate its privileges

and potentially gain access outside of the namespace.

(https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1527374)

Topics%20covered

Topics Covered

security advisory Ubuntu update instructions kernel issue Raspberry Pi namespace access ptrace issue

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 15.10:
  linux-image-4.2.0-1017-raspi2   4.2.0-1017.24

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

https://ubuntu.com/security/notices/USN-2852-1

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1527374

Severity
critical
Lowest
Low
Medium
High
Critical

December 19, 2015

Topics%20covered

Topics Covered

security advisory Ubuntu update instructions kernel issue Raspberry Pi namespace access ptrace issue

Package Information

https://launchpad.net/ubuntu/+source/linux-raspi2/4.2.0-1017.24

Get the latest News and Insights

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