Ubuntu Security Notice USN-776-1

12th May, 2009

kvm vulnerabilities

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

• Ubuntu 8.10
• Ubuntu 8.04 LTS

Software description

• kvm

Details

Avi Kivity discovered that KVM did not correctly handle certain disk
formats. A local attacker could attach a malicious partition that
would allow the guest VM to read files on the VM host. (CVE-2008-1945,
CVE-2008-2004)

Alfredo Ortega discovered that KVM's VNC protocol handler did not
correctly validate certain messages. A remote attacker could send
specially crafted VNC messages that would cause KVM to consume CPU
resources, leading to a denial of service. (CVE-2008-2382)

Jan Niehusmann discovered that KVM's Cirrus VGA implementation over VNC
did not correctly handle certain bitblt operations. A local attacker
could exploit this flaw to potentially execute arbitrary code on the VM
host or crash KVM, leading to a denial of service. (CVE-2008-4539)

It was discovered that KVM's VNC password checks did not use the correct
length. A remote attacker could exploit this flaw to cause KVM to crash,
leading to a denial of service. (CVE-2008-5714)

Update instructions

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

Ubuntu 8.10:

kvm 1:72+dfsg-1ubuntu6.1

Ubuntu 8.04 LTS:

kvm 1:62+dfsg-0ubuntu8.1

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system upgrade you need to restart all KVM VMs to effect
the necessary changes.

References

CVE-2008-1945, CVE-2008-2004, CVE-2008-2382, CVE-2008-4539, CVE-2008-5714