PT-2018-11454 · Xen+1 · Xen+1
Jan Beulich
·
Published
2018-06-27
·
Updated
2024-06-15
·
CVE-2018-12891
CVSS v3.1
6.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Xen versions 3.3 and earlier
Xen versions 3.4 through 4.10.x
Description
An issue in Xen allows a malicious or buggy PV guest to cause a Denial of Service (DoS) affecting the entire host, specifically by preventing use of a physical CPU for an indeterminate period of time. This occurs because certain PV MMU operations may take a long time to process, and a malicious guest can cause rarely taken code paths to bypass checks for the need to preempt the current vCPU. The vulnerability can be leveraged by multi-vCPU x86 PV guests, but x86 HVM or PVH guests as well as x86 single-vCPU PV ones cannot leverage the vulnerability. Only x86 systems are affected, while ARM systems are not.
Recommendations
For Xen versions 3.3 and earlier, consider disabling multi-vCPU support for PV guests to minimize the risk of exploitation.
For Xen versions 3.4 through 4.10.x, consider restricting the use of physical CPUs by PV guests to prevent a Denial of Service (DoS) affecting the entire host.
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
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Related Identifiers
Affected Products
Suse
Xen