Description
An issue was discovered in Xen through 4.13.x, allowing Arm guest OS users to cause a hypervisor crash because of a missing alignment check in VCPUOP_register_vcpu_info. The hypercall VCPUOP_register_vcpu_info is used by a guest to register a shared region with the hypervisor. The region will be mapped into Xen address space so it can be directly accessed. On Arm, the region is accessed with instructions that require a specific alignment. Unfortunately, there is no check that the address provided by the guest will be correctly aligned. As a result, a malicious guest could cause a hypervisor crash by passing a misaligned address. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). All Xen versions are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| n/a | n/a | n/a |
References
- http://www.openwall.com/lists/oss-security/2020/07/07/5Mailing List, Patch, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-327.htmlPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP/
- https://security.gentoo.org/glsa/202007-02Third Party Advisory
- https://www.debian.org/security/2020/dsa-4723Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/07/07/5Mailing List, Patch, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-327.htmlPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP/
- https://security.gentoo.org/glsa/202007-02Third Party Advisory
- https://www.debian.org/security/2020/dsa-4723Third Party Advisory
Timeline
- Published
- Jul 7, 2020
- Last modified
- Jun 17, 2026
- NVD status
- Modified