Xen 3.1 through 4.x, when running 64-bit hosts on Intel CPUs, does not clear the NT flag when using an IRET after a SYSENTER instruction, which allows PV guest users to cause a denial of service (hypervisor crash) by triggering a #GP fault, which is not properly handled by another IRET instruction.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2013-1917 from the MITRE CVE dictionary dictionary and NIST NVD.
Not vulnerable.
This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5 as we did not have support for sysenter for 64bit PV guests running on the Xen hypervisor (introduced in upstream changeset 16207:aeebd173c3fa).
This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as we did not have support for Xen hypervisor.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
Base Score | 5.7 |
---|---|
Base Metrics | AV:A/AC:M/Au:N/C:N/I:N/A:C |
Access Vector | Adjacent Network |
Access Complexity | Medium |
Authentication | None |
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 | Not affected |
Red Hat Enterprise Linux 5 | kernel | Not affected |