{"id":"CVE-2020-15564","details":"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.","modified":"2026-03-13T00:31:11.607752Z","published":"2020-07-07T13:15:10.023Z","references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP/"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202007-02"},{"type":"ADVISORY","url":"https://www.debian.org/security/2020/dsa-4723"},{"type":"FIX","url":"http://www.openwall.com/lists/oss-security/2020/07/07/5"},{"type":"FIX","url":"http://xenbits.xen.org/xsa/advisory-327.html"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"4.8.0"},{"last_affected":"4.13.1"}]},{"events":[{"introduced":"0"},{"last_affected":"10.0"}]},{"events":[{"introduced":"0"},{"last_affected":"31"}]},{"events":[{"introduced":"0"},{"last_affected":"32"}]}],"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-15564.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"}]}