04 Dec 2012
18 Jan 2013
DoS (Denial of Service)
This includes vulnerabilities ranging from excessive resource consumption (e.g. causing a system to use a lot of memory) to crashing an application or an entire system.
This covers vulnerabilities where a user is able to conduct certain tasks with the privileges of other users or administrative users.
This typically includes cases where a local user on a client or server system can gain access to the administrator or root account thus taking full control of the system.
Multiple vulnerabilities have been reported in Xen, which can be exploited by malicious, local users in a guest virtual machine to cause a DoS (Denial of Service) and potentially gain escalated privileges.
1) An error when downgrading a grant table version of a guest can be exploited to cause a hypervisor crash.
2) An error when handling certain HVM control operations can be exploited to consume physical CPU resources.
3) An array-indexing error in the "HVMOP_set_mem_access" operation handler can be exploited to cause a crash.
4) An error in the "XENMEM_exchange" handler may result in guest provided addresses to be included in the hypervisor's reserved range.
5) An error in the "guest_physmap_mark_populate_on_demand()" function when checking subject GFNs can be exploited to cause a hang.
6) An error when handling "extent_order" values for "XENMEM_decrease_reservation", "XENMEM_populate_physmap", and "XENMEM_exchange" can be exploited to cause a hang.
7) An error in the "get_page_from_gfn()" function when handling an input GFN can be exploited to reference memory outside of the frame table.
Please see the vendor's advisory for a list of affected versions.
Apply patches (please see the vendor's advisory for details).
Reported by the vendor.
Xen (XSA-26, XSA-27, XSA-28, XSA-29, XSA-30, XSA-31, XSA-32):