# CVE-2020-15564: libxenevtchn1: An issue was discovered in Xen through 4.13.x, allowing Arm guest OS users to cause a hypervisor crash because of a m... CVE-2020-15564 is fixed in 22 products on 1 platform, first by libxencall1 4.11.3+24-g14b62ab3e5-1ubuntu2.3, released September 23, 2020. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2020-15564 - Priority: Routine - CVSS: n/a (Medium) - EPSS: 0.0040 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 7, 2020 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | libxencall1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxencall1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxencall1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxendevicemodel1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxendevicemodel1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxendevicemodel1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxenevtchn1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxenevtchn1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxenevtchn1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxenforeignmemory1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxenforeignmemory1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxenforeignmemory1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxengnttab1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxengnttab1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxengnttab1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxenmisc4.11 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxenmisc4.11 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxenmisc4.11-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxenstore3.0 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxenstore3.0 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxenstore3.0-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxentoolcore1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxentoolcore1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxentoolcore1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | libxentoollog1 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [libxentoollog1 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxentoollog1-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.11-amd64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.11-amd64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.11-amd64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.11-arm64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.11-arm64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.11-arm64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.11-armhf Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.11-armhf 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.11-armhf-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.9-amd64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.9-amd64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.9-amd64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.9-arm64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.9-arm64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.9-arm64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-4.9-armhf Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-4.9-armhf 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-4.9-armhf-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-hypervisor-common Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-hypervisor-common 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-hypervisor-common-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-system-amd64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-system-amd64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-system-amd64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-system-arm64 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-system-arm64 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-system-arm64-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-system-armhf Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-system-armhf 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-system-armhf-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-utils-4.11 Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-utils-4.11 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-utils-4.11-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xen-utils-common Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xen-utils-common 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xen-utils-common-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | | Linux | xenstore-utils Ubuntu 20.04 LTS (focal) | 4.11.3+24-g14b62ab3e5-1ubuntu2.3 | [xenstore-utils 4.11.3+24-g14b62ab3e5-1ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xenstore-utils-4.11.3-24-g14b62ab3e5-1ubuntu2.3.md) | Sep 23, 2020 | --- Data as of 2026-11-08T00:53:09Z UTC. 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