Certain page table manipulation operations in Xen 4.1.x, 4.2.x, and earlier are not preemptible, which allows local PV kernels to cause a denial of service via vectors related to "deep page table traversal."
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2013-1918 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue did affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.
This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG 2.
The risks associated with fixing this bug are greater than its security impact. This issue is not currently planned to be addressed in future kernel-xen updates for Red Hat Enterprise Linux 5. Using fully virtualized (HVM) guests, or PV guests with trusted kernel/administrator avoids this issue.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 5.2 |
|---|---|
| Base Metrics | AV:A/AC:M/Au:S/C:N/I:N/A:C |
| Access Vector | Adjacent Network |
| Access Complexity | Medium |
| Authentication | Single |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Complete |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected |
| Red Hat Enterprise Linux 6 | kernel | Not affected |
| Red Hat Enterprise Linux 5 | kernel-xen | Will not fix |
Vulmon