National Vulnerability Database

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CVE-2018-12891 Detail

Current Description

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions through its own page table contents, a malicious guest may cause such bypasses to be used for an unbounded number of iterations. A malicious or buggy PV guest may cause a Denial of Service (DoS) affecting the entire host. Specifically, it may prevent use of a physical CPU for an indeterminate period of time. All Xen versions from 3.4 onwards are vulnerable. Xen versions 3.3 and earlier are vulnerable to an even wider class of attacks, due to them lacking preemption checks altogether in the affected code paths. Only x86 systems are affected. ARM systems are not affected. Only multi-vCPU x86 PV guests can leverage the vulnerability. x86 HVM or PVH guests as well as x86 single-vCPU PV ones cannot leverage the vulnerability.


View Analysis Description

Severity

 


CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  6.5 MEDIUM
Vector:  CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://www.openwall.com/lists/oss-security/2018/06/27/10 Mailing List  Patch  Third Party Advisory 
http://www.securityfocus.com/bid/104570 Third Party Advisory  VDB Entry 
http://www.securitytracker.com/id/1041201 Third Party Advisory  VDB Entry 
http://xenbits.xen.org/xsa/advisory-264.html Patch  Vendor Advisory 
https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html Issue Tracking  Third Party Advisory 
https://security.gentoo.org/glsa/201810-06 Third Party Advisory 
https://support.citrix.com/article/CTX235748 Third Party Advisory 
https://www.debian.org/security/2018/dsa-4236 Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  

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Change History

6 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2018-12891
NVD Published Date:
07/02/2018
NVD Last Modified:
10/02/2019
Source:
MITRE