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CVE-2017-15597: Xen: Privilege escalation

CVE-2017-15597 is rated critical with a CVSS v3.0 base score of 9.1 and affects Xen. Per its scoring, it can be exploited over the network, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An issue was discovered in Xen through 4.9.x. Grant copying code made an implication that any grant pin would be accompanied by a suitable page reference. Other portions of code, however, did not match up with that assumption. When such a grant copy operation is being done on a grant of a dying domain, the assumption turns out wrong. A malicious guest administrator can cause hypervisor memory corruption, most likely resulting in host crash and a Denial of Service. Privilege escalation and information leaks cannot be ruled out.

Severity breakdown

CVSS v3.0 9.1: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: High. Administrative-level privileges are needed.
User interaction: None. No action from any user is needed.
Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Affected products

Xen: up to and including 4.9.0