U radu jezgre operacijskog sustava Ubuntu Linux za EC2 uočena su tri sigurnosna propusta. Lokalni ih napadači mogu iskoristiti za zaobilaženje postavljenih ograničenja, izmjenu podataka, izvođenje DoS napada i izvršavanje proizvoljnog programskog koda.

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Ubuntu Security Notice USN-1388-1
March 06, 2012

linux-ec2 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 10.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux-ec2: Linux kernel for EC2

Details:

Paolo Bonzini discovered a flaw in Linux's handling of the SG_IO ioctl
command. A local user, or user in a VM could exploit this flaw to bypass
restrictions and gain read/write access to all data on the affected block
device. (CVE-2011-4127)

A flaw was found in KVM's Programmable Interval Timer (PIT). When a virtual
interrupt control is not available a local user could use this to cause a
denial of service by starting a timer. (CVE-2011-4622)

A flaw was discovered in the XFS filesystem. If a local user mounts a
specially crafted XFS image it could potential execute arbitrary code on
the system. (CVE-2012-0038)

Update instructions:

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

Ubuntu 10.04 LTS:
  linux-image-2.6.32-343-ec2      2.6.32-343.45

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-1388-1
  CVE-2011-4127, CVE-2011-4622, CVE-2012-0038

Package Information:
  https://launchpad.net/ubuntu/+source/linux-ec2/2.6.32-343.45