Description
An issue was discovered in Xen through 4.12.x allowing x86 HVM/PVH guest OS users to cause a denial of service (guest OS crash) because VMX VMEntry checks mishandle a certain case. Please see XSA-260 for background on the MovSS shadow. Please see XSA-156 for background on the need for #DB interception. The VMX VMEntry checks do not like the exact combination of state which occurs when #DB in intercepted, Single Stepping is active, and blocked by STI/MovSS is active, despite this being a legitimate state to be in. The resulting VMEntry failure is fatal to the guest. HVM/PVH guest userspace code may be able to crash the guest, resulting in a guest Denial of Service. All versions of Xen are affected. Only systems supporting VMX hardware virtual extensions (Intel, Cyrix, or Zhaoxin CPUs) are affected. Arm and AMD systems are unaffected. Only HVM/PVH guests are affected. PV guests cannot leverage the vulnerability.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | xen | 4.11.3+24-g14b62ab3e5-1 | — |
| Debian 13 | xen | 4.11.3+24-g14b62ab3e5-1 | — |
| Debian 12 | xen | 4.11.3+24-g14b62ab3e5-1 | — |
| Debian 10 | xen | 4.11.3+24-g14b62ab3e5-1~deb10u1 | DSA-4602-1 |
| Debian 9 | xen | 4.8.5.final+shim4.10.4-1+deb9u12 | DSA-4602-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | xen | No fix yet | — |
| Ubuntu 16.04 LTS | xen | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | xen | 4.12.1_06-3.9.1 | SUSE-SU-2019:3338-1 |
| SLES 15 | xen | 4.10.4_08-3.28.1 | SUSE-SU-2019:3309-1 |
| SLES 12 SP5 | xen | 4.12.1_10-3.8.1 | SUSE-SU-2019:3296-1 |
| SLES 12 SP4 | xen | 4.11.3_02-2.20.1 | SUSE-SU-2019:3310-1 |
| SLES 12 SP3 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | xen | 4.7.6_06-43.59.1 | SUSE-SU-2020:0334-1 |
| SLES 12 SP1 | xen | 4.5.5_28-22.64.1 | SUSE-SU-2020:0388-1 |
| SLES 11 SP4 | xen | 4.4.4_42-61.52.1 | SUSE-SU-2020:14444-1 |
| SLES for SAP 12 SP5 | xen | 4.12.1_10-3.8.1 | SUSE-SU-2019:3296-1 |
| SLES for SAP 12 SP4 | xen | 4.11.3_02-2.20.1 | SUSE-SU-2019:3310-1 |
| SLES for SAP 12 SP3 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
| SLES for SAP 12 SP2 | xen | 4.7.6_06-43.59.1 | SUSE-SU-2020:0334-1 |
| SLES for SAP 12 SP1 | xen | 4.5.5_28-22.64.1 | SUSE-SU-2020:0388-1 |
| SUSE OpenStack Cloud Crowbar 8 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
| SUSE OpenStack Cloud 8 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
| SUSE OpenStack Cloud 7 | xen | 4.7.6_06-43.59.1 | SUSE-SU-2020:0334-1 |
| SUSE HPE Helion OpenStack 8 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
| SUSE Enterprise Storage 5 | xen | 4.9.4_06-3.59.1 | SUSE-SU-2020:1630-1, SUSE-SU-2019:3297-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | xen | 4.12.1_06-lp151.2.9.1 | openSUSE-SU-2020:0011-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.13.0-r0 | — |
| Alpine v3.23 | xen | 4.13.0-r0 | — |
| Alpine v3.22 | xen | 4.13.0-r0 | — |
| Alpine v3.21 | xen | 4.13.0-r0 | — |
| Alpine v3.20 | xen | 4.13.0-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | xen | 4.13.0-r0 | — |
| Alpine v3.18 | xen | 4.13.0-r0 | — |
| Alpine v3.17 | xen | 4.13.0-r0 | — |
| Alpine v3.16 | xen | 4.13.0-r0 | — |
| Alpine v3.15 | xen | 4.13.0-r0 | — |
| Alpine v3.14 | xen | 4.13.0-r0 | — |
| Alpine v3.13 | xen | 4.13.0-r0 | — |
| Alpine v3.12 | xen | 4.13.0-r0 | — |
| Alpine v3.11 | xen | 4.13.0-r0 | — |
| Alpine v3.10 | xen | 4.12.2-r0 | — |
| Alpine v3.9 | xen | 4.11.3-r1 | — |
| Alpine v3.8 | xen | 4.10.4-r2 | — |
Advisories 11
- DSA-4602-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2019:3338-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0334-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1630-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0011-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3309-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14444-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3297-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3310-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3296-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0388-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://xenbits.xen.org/xsa/advisory-308.html
- FEDORA-2019-6aad703290 vendor-advisory
- FEDORA-2019-2e12bd3a9a vendor-advisory
- openSUSE-SU-2020:0011 vendor-advisory
- DSA-4602 vendor-advisory
- 20200114 [SECURITY] [DSA 4602-1] xen security update mailing-list
- GLSA-202003-56 vendor-advisory