# CVE-2020-15566: libxencall1: An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect... CVE-2020-15566 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-2020-15566 - Priority: Routine - CVSS: n/a (Medium) - EPSS: 0.0041 - 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 guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit. ## 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. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.