USN-1796-1: Linux kernel vulnerabilities

8 April 2013

linux vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 12.10

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux - Linux kernel

Details

Andrew Jones discovered a flaw with the xen_iret function in Linux kernel’s Xen virtualizeation. In the 32-bit Xen paravirt platform an unprivileged guest OS user could exploit this flaw to cause a denial of service (crash the system) or gain guest OS privilege. (CVE-2013-0228)

Emese Revfy discovered that in the Linux kernel signal handlers could leak address information across an exec, making it possible to by pass ASLR (Address Space Layout Randomization). A local user could use this flaw to by pass ASLR to reliably deliver an exploit payload that would otherwise be stopped (by ASLR). (CVE-2013-0914)

A memory use after free error was discover in the Linux kernel’s tmpfs filesystem. A local user could exploit this flaw to gain privileges or cause a denial of service (system crash). (CVE-2013-1767)

Mateusz Guzik discovered a race in the Linux kernel’s keyring. A local user could exploit this flaw to cause a denial of service (system crash). (CVE-2013-1792)

Mathias Krause discovered a memory leak in the Linux kernel’s crypto report API. A local user with CAP_NET_ADMIN could exploit this leak to examine some of the kernel’s stack memory. (CVE-2013-2546)

Mathias Krause discovered a memory leak in the Linux kernel’s crypto report API. A local user with CAP_NET_ADMIN could exploit this leak to examine some of the kernel’s heap memory. (CVE-2013-2547)

Mathias Krause discovered information leaks in the Linux kernel’s crypto algorithm report API. A local user could exploit these flaws to leak kernel stack and heap memory contents. (CVE-2013-2548)

Update instructions

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

Ubuntu 12.10
linux-image-3.5.0-27-generic - 3.5.0-27.46
linux-image-3.5.0-27-highbank - 3.5.0-27.46
linux-image-3.5.0-27-omap - 3.5.0-27.46
linux-image-3.5.0-27-powerpc-smp - 3.5.0-27.46
linux-image-3.5.0-27-powerpc64-smp - 3.5.0-27.46

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well.

References