CVE Vulnerabilities

CVE-2018-15469

Uncontrolled Resource Consumption

Published: Aug 17, 2018 | Modified: Nov 21, 2024
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
CVSS 2.x
4.9 MEDIUM
AV:L/AC:L/Au:N/C:N/I:N/A:C
RedHat/V2
RedHat/V3
6 MODERATE
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
Ubuntu
MEDIUM

An issue was discovered in Xen through 4.11.x. ARM never properly implemented grant table v2, either in the hypervisor or in Linux. Unfortunately, an ARM guest can still request v2 grant tables; they will simply not be properly set up, resulting in subsequent grant-related hypercalls hitting BUG() checks. An unprivileged guest can cause a BUG() check in the hypervisor, resulting in a denial-of-service (crash).

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Name Vendor Start Version End Version
Xen Xen * 4.11.0 (including)
Xen Ubuntu bionic *
Xen Ubuntu cosmic *
Xen Ubuntu disco *
Xen Ubuntu eoan *
Xen Ubuntu esm-infra/bionic *
Xen Ubuntu esm-infra/xenial *
Xen Ubuntu groovy *
Xen Ubuntu hirsute *
Xen Ubuntu impish *
Xen Ubuntu trusty *
Xen Ubuntu upstream *
Xen Ubuntu xenial *

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References