The fbld instruction emulation in Xen 3.3.x through 4.3.x does not use the correct variable for the source effective address, which allows local HVM guests to obtain hypervisor stack information by reading the values used by the instruction.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2013-4361 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue does not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.
This issue does not affect the versions of the Linux kernel package as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as it does not have support for Xen hypervisor.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 1 |
|---|---|
| Base Metrics | AV:L/AC:H/Au:S/C:P/I:N/A:N |
| Access Vector | Local |
| Access Complexity | High |
| Authentication | Single |
| Confidentiality Impact | Partial |
| Integrity Impact | None |
| Availability Impact | None |
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 7 | kernel | Not affected |
| Red Hat Enterprise Linux 6 | kernel | Not affected |
| Red Hat Enterprise Linux 5 | kernel-xen | Not affected |
Vulmon