Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in denial of service, guest-to-host privilege escalation or information leaks.

In addition this update provides mitigations for the TSX Asynchronous Abort speculative side channel attack. For additional information please refer to https://xenbits.xen.org/xsa/advisory-305.html

For the oldstable distribution (stretch), these problems have been fixed in version 4.8.5.final+shim4.10.4-1+deb9u12. Note that this will be the last security update for Xen in the oldstable distribution; upstream support for the 4.8.x branch ended by the end of December 2019. If you rely on security support for your Xen installation an update to the stable distribution (buster) is recommended.

For the stable distribution (buster), these problems have been fixed in version 4.11.3+24-g14b62ab3e5-1~deb10u1.

We recommend that you upgrade your xen packages.

For the detailed security status of xen please refer to its security tracker page at: https://security-tracker.debian.org/tracker/xen