National Vulnerability Database

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CVE-2018-12892 Detail

Current Description

An issue was discovered in Xen 4.7 through 4.10.x. libxl fails to pass the readonly flag to qemu when setting up a SCSI disk, due to what was probably an erroneous merge conflict resolution. Malicious guest administrators or (in some situations) users may be able to write to supposedly read-only disk images. Only emulated SCSI disks (specified as "sd" in the libxl disk configuration, or an equivalent) are affected. IDE disks ("hd") are not affected (because attempts to make them readonly are rejected). Additionally, CDROM devices (that is, devices specified to be presented to the guest as CDROMs, regardless of the nature of the backing storage on the host) are not affected; they are always read only. Only systems using qemu-xen (rather than qemu-xen-traditional) as the device model version are vulnerable. Only systems using libxl or libxl-based toolstacks are vulnerable. (This includes xl, and libvirt with the libxl driver.) The vulnerability is present in Xen versions 4.7 and later. (In earlier versions, provided that the patch for XSA-142 has been applied, attempts to create read only disks are rejected.) If the host and guest together usually support PVHVM, the issue is exploitable only if the malicious guest administrator has control of the guest kernel or guest kernel command line.


View Analysis Description

Severity

 


CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  9.9 CRITICAL
Vector:  CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/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/2018/06/27/12 Mailing List  Third Party Advisory 
http://www.securityfocus.com/bid/104571 Third Party Advisory  VDB Entry 
http://www.securitytracker.com/id/1041203 Third Party Advisory  VDB Entry 
http://xenbits.xen.org/xsa/advisory-266.html Vendor Advisory 
https://security.gentoo.org/glsa/201810-06 Third Party Advisory 
https://www.debian.org/security/2018/dsa-4236 Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor cwe source acceptance level NIST  

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2018-12892
NVD Published Date:
07/02/2018
NVD Last Modified:
03/29/2019
Source:
MITRE