USN-1756-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-1756-1

6th March, 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 version:

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

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

CVE-2013-0216, CVE-2013-0217, CVE-2013-0228, CVE-2013-0268, CVE-2013-0311, CVE-2013-0349, CVE-2013-1773