A number of security vulnerabilities have been identified in Citrix XenServer. These vulnerabilities affect all currently supported versions of Citrix XenServer up to and including version 6.0.2.
The following issues have been addressed:
• 64-bit PV guest to host privilege escalation vulnerability. This issue only impacts servers running on Intel processors and could permit a 64-bit PV guest to compromise the XenServer host (CVE-2012-0217).
• Guest denial of service on syscall/sysenter exception generation. This issue could permit user code within a PV guest to crash the guest operating system (CVE-2012-0218).
• Administrative connections to VM consoles through XAPI or XenCenter could be routed to the wrong VM.
Mitigating Factors
Customers that are using only Windows guests, which are never PV guests, are unaffected by the first two issues described above. Customers should refer to the XenServer product documentation for more information on the types of guests available.
What Customers Should Do
Hotfixes have been released to address these issues in all supported versions and update levels of Citrix XenServer. Citrix strongly recommends that customers using Citrix XenServer identify and apply the hotfixes that relate to their deployed versions:
Citrix XenServer 6.0.2:
http://support.citrix.com/article/CTX133166
http://support.citrix.com/article/CTX133174
Citrix XenServer 6.0.0:
http://support.citrix.com/article/CTX133165
http://support.citrix.com/article/CTX133173
Citrix XenServer 5.6 Service Pack 2:
http://support.citrix.com/article/CTX133175
http://support.citrix.com/article/CTX133172
Citrix XenServer 5.6 Feature Pack 1:
http://support.citrix.com/article/CTX133176
http://support.citrix.com/article/CTX133171
Citrix XenServer 5.6:
http://support.citrix.com/article/CTX133180
Citrix XenServer 5.5 Update 2:
http://support.citrix.com/article/CTX133179
http://support.citrix.com/article/CTX133168
Citrix XenServer 5.0 Update 3:
http://support.citrix.com/article/CTX133177
http://support.citrix.com/article/CTX133167
Customers using Citrix XenServer 5.6 in the Common Criteria evaluated configuration should apply the following hotfix:
http://support.citrix.com/article/CTX133184
You can read the entire article here on the Citrix KB support page.