What is the CVSS score of CVE-2018-12892?

CVE-2018-12892 has a CVSS 3.0 base score of 9.9 (Critical). CVSS vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 2.6%.

Debian Linux CVE-2018-12892

CRITICAL

Information Exposure (CWE-200)

2018-07-02 cve@mitre.org

Information Disclosure Debian Debian Linux Xen

9.9

CVSS 3.0 · NVD

Severity by source

NVD PRIMARY

9.9 CRITICAL

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Jul 02, 2018 - 17:29 nvd

CRITICAL 9.9

DescriptionNVD

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.

AnalysisAI

An issue was discovered in Xen 4.7 through 4.10.x. Rated critical severity (CVSS 9.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Exposure of Sensitive Information (CWE-200), which allows attackers to access sensitive data that should not be disclosed. 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. Affected products include: Debian Debian Linux, Xen. Version information: through 4.10..

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Minimize information in error messages, implement proper access controls, encrypt sensitive data at rest and in transit.