USN-1776-1: Linux kernel (EC2) vulnerabilities

Ubuntu Security Notice USN-1776-1

22nd March, 2013

linux-ec2 vulnerabilities

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

  • Ubuntu 10.04 LTS


Several security issues were fixed in the kernel.

Software description

  • linux-ec2 - Linux kernel for EC2


A flaw was reported in the permission checks done by the Linux kernel for
/dev/cpu/*/msr. A local root user with all capabilities dropped could
exploit this flaw to execute code with full root capabilities.

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).

A flaw was discovered on the Linux kernel's VFAT filesystem driver when a
disk is mounted with the utf8 option (this is the default on Ubuntu). On a
system where disks/images can be auto-mounted or a FAT filesystem is
mounted an unprivileged user can exploit the flaw to gain root privileges.

Update instructions

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

Ubuntu 10.04 LTS:
linux-image-2.6.32-351-ec2 2.6.32-351.62

To update your system, please follow these instructions:

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.


CVE-2013-0268, CVE-2013-0309, CVE-2013-1773