Description
An issue was discovered in Xen through 4.12.x allowing 32-bit Arm guest OS users to cause a denial of service (out-of-bounds access) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On 32-bit Arm accesses to bitmaps with bit a count which is a multiple of 32, an out of bounds access may occur. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. 32-bit Arm systems are vulnerable. 64-bit Arm systems are not vulnerable.
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 12 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 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 |
Advisories 10
- 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-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-307.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