Description
An issue was discovered in Xen through 4.9.x allowing guest OS users to cause a denial of service (host OS crash) or gain host OS privileges by leveraging an incorrect mask for reference-count overflow checking in shadow mode.
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 | 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 | — |
| Debian 13 | xen | 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 | — |
| Debian 12 | xen | 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 | — |
| Debian 9 | xen | 4.8.3+comet2+shim4.10.0+comet3-1+deb9u4.1 | DSA-4112-1 |
| Debian 8 | xen | 4.4.4lts2-0+deb8u1 | DLA-1549-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | xen | 4.1.6.lts1-11 | DLA-1230-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | xen | 4.9.2-0ubuntu1 | — |
| Ubuntu 16.04 LTS | xen | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | xen | 4.9.1_08-3.26.1 | SUSE-SU-2018:0438-1 |
| SLES 12 SP2 | xen | 4.7.4_06-43.24.1 | SUSE-SU-2018:0472-1 |
| SLES 12 SP1 | xen | 4.5.5_24-22.43.1 | SUSE-SU-2018:0609-1 |
| SLES 12 | xen | 4.4.4_28-22.62.1 | SUSE-SU-2018:0601-1 |
| SLES 11 SP4 | xen | 4.4.4_28-61.23.2 | SUSE-SU-2018:0638-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | xen | 4.2.5_21-45.19.1 | SUSE-SU-2018:0678-1 |
| SLES for SAP 12 SP3 | xen | 4.9.1_08-3.26.1 | SUSE-SU-2018:0438-1 |
| SLES for SAP 12 SP2 | xen | 4.7.4_06-43.24.1 | SUSE-SU-2018:0472-1 |
| SLES for SAP 12 SP1 | xen | 4.5.5_24-22.43.1 | SUSE-SU-2018:0609-1 |
| SLES for SAP 11 SP4 | xen | 4.4.4_28-61.23.2 | SUSE-SU-2018:0638-1 |
| SUSE OpenStack Cloud 6 | xen | 4.5.5_24-22.43.1 | SUSE-SU-2018:0609-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | xen | 4.2.5_21-45.19.1 | SUSE-SU-2018:0678-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.6 | xen | 4.8.2-r5 | — |
| Alpine v3.5 | xen | 4.7.3-r5 | — |
| Alpine v3.4 | xen | 4.6.6-r3 | — |
Advisories 9
- DLA-1549-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4112-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1230-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:0472-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0601-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0638-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0678-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0609-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0438-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
References
- 102169 vdb-entry
- 1040769 vdb-entry
- [debian-lts-announce] 20180105 [SECURITY] [DLA 1230-1] xen security update mailing-list
- [debian-lts-announce] 20181018 [SECURITY] [DLA 1549-1] xen security update mailing-list
- http://www.openwall.com/lists/oss-security/2017/12/12/2
- GLSA-201801-14 vendor-advisory
- https://xenbits.xen.org/xsa/advisory-249.html
- DSA-4112 vendor-advisory
- https://support.citrix.com/article/CTX232096