USN-1646-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-1646-1

30th November, 2012

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


Brad Spengler discovered a flaw in the Linux kernel's uname system call. An
unprivileged user could exploit this flaw to read kernel stack memory.
(CVE-2012-0957)

Rodrigo Freire discovered a flaw in the Linux kernel's TCP illinois
congestion control algorithm. A local attacker could use this to cause a
denial of service. (CVE-2012-4565)

Mathias Krause discovered a flaw in the Linux kernel's XFRM netlink
interface. A local user with the NET_ADMIN capability could exploit this
flaw to leak the contents of kernel memory. (CVE-2012-6536)

Mathias Krause discovered several errors in the Linux kernel's xfrm_user
implementation. A local attacker could exploit these flaws to examine parts
of kernel memory. (CVE-2012-6537)

Mathias Krause discovered an information leak in the Linux kernel's
xfrm_user copy_to_user_auth function. A local user could exploit this flaw
to examine parts of kernel heap memory. (CVE-2012-6538)

A flaw was discovered in the Linux kernels handling of memory ranges with
PROT_NONE when transparent hugepages are in use. An unprivileged local user
could exploit this flaw to cause a denial of service (crash the system).
(CVE-2013-0309)

Mathias Krause discovered a flaw in xfrm_user in the Linux kernel. A local
attacker with NET_ADMIN capability could potentially exploit this flaw to
escalate privileges. (CVE-2013-1826)

Update instructions

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

Ubuntu 12.10:
linux-image-3.5.0-19-highbank 3.5.0-19.30
linux-image-3.5.0-19-omap 3.5.0-19.30
linux-image-3.5.0-19-generic 3.5.0-19.30
linux-image-3.5.0-19-powerpc-smp 3.5.0-19.30
linux-image-3.5.0-19-powerpc64-smp 3.5.0-19.30

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.

References

CVE-2012-0957, CVE-2012-4565, CVE-2012-6536, CVE-2012-6537, CVE-2012-6538, CVE-2013-0309, CVE-2013-1826