[USN-1756-1] Linux kernel vulnerabilities

[John Johansen]

==========================================================================
Ubuntu Security Notice USN-1756-1
March 06, 2013

linux vulnerabilities
==========================================================================

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

- Ubuntu 11.10

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux: Linux kernel

Details:

A failure to validate input was discovered in the Linux kernel's Xen
netback (network backend) driver. A user in a guest OS may exploit this
flaw to cause a denial of service to the guest OS and other guest domains.
(CVE-2013-0216)

A memory leak was discovered in the Linux kernel's Xen netback (network
backend) driver. A user in a guest OS could trigger this flaw to cause a
denial of service on the system. (CVE-2013-0217)

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)

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.
(CVE-2013-0268)

A flaw was discovered in the Linux kernel's vhost driver used to accelerate
guest networking in KVM based virtual machines. A privileged guest user
could exploit this flaw to crash the host system. (CVE-2013-0311)

An information leak was discovered in the Linux kernel's Bluetooth stack
when HIDP (Human Interface Device Protocol) support is enabled. A local
unprivileged user could exploit this flaw to cause an information leak from
the kernel. (CVE-2013-0349)

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.
(CVE-2013-1773)

Update instructions:

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

Ubuntu 11.10:
  linux-image-3.0.0-32-generic    3.0.0-32.50
  linux-image-3.0.0-32-generic-pae  3.0.0-32.50
  linux-image-3.0.0-32-omap       3.0.0-32.50
  linux-image-3.0.0-32-powerpc    3.0.0-32.50
  linux-image-3.0.0-32-powerpc-smp  3.0.0-32.50
  linux-image-3.0.0-32-powerpc64-smp  3.0.0-32.50
  linux-image-3.0.0-32-server     3.0.0-32.50
  linux-image-3.0.0-32-virtual    3.0.0-32.50

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:
  http://www.ubuntu.com/usn/usn-1756-1
  CVE-2013-0216, CVE-2013-0217, CVE-2013-0228, CVE-2013-0268,
  CVE-2013-0311, CVE-2013-0349, CVE-2013-1773

Package Information:
  https://launchpad.net/ubuntu/+source/linux/3.0.0-32.50

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