Description
An issue was discovered in Xen through 4.11.x. The logic in oxenstored for handling writes depended on the order of evaluation of expressions making up a tuple. As indicated in section 7.7.3 "Operations on data structures" of the OCaml manual, the order of evaluation of subexpressions is not specified. In practice, different implementations behave differently. Thus, oxenstored may not enforce the configured quota-maxentity. This allows a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS.
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 | 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | — |
| Debian 13 | xen | 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | — |
| Debian 12 | xen | 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | — |
| Debian 9 | xen | 4.8.4+xsa273+shim4.10.1+xsa273-1+deb9u10 | DSA-4274-1 |
| Debian 8 | xen | 4.4.4lts4-0+deb8u1 | DLA-1577-1 |
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 | xen | 4.10.2_04-3.9.1 | SUSE-SU-2018:4300-1 |
| SLES 12 SP3 | xen | 4.9.3_03-3.44.2 | SUSE-SU-2018:3490-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | xen | 4.9.3_03-3.44.2 | SUSE-SU-2018:3490-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.15.1_01-1.2 | openSUSE-SU-2024:11520-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.11.1-r0 | — |
| Alpine v3.23 | xen | 4.11.1-r0 | — |
| Alpine v3.22 | xen | 4.11.1-r0 | — |
| Alpine v3.21 | xen | 4.11.1-r0 | — |
| Alpine v3.20 | xen | 4.11.1-r0 | — |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | xen | 4.11.1-r0 | — |
| Alpine v3.18 | xen | 4.11.1-r0 | — |
| Alpine v3.17 | xen | 4.11.1-r0 | — |
| Alpine v3.16 | xen | 4.11.1-r0 | — |
| Alpine v3.15 | xen | 4.11.1-r0 | — |
| Alpine v3.14 | xen | 4.11.1-r0 | — |
| Alpine v3.13 | xen | 4.11.1-r0 | — |
| Alpine v3.12 | xen | 4.11.1-r0 | — |
| Alpine v3.11 | xen | 4.11.1-r0 | — |
| Alpine v3.10 | xen | 4.11.1-r0 | — |
| Alpine v3.9 | xen | 4.11.1-r0 | — |
| Alpine v3.8 | xen | 4.10.1-r3 | — |
| Alpine v3.7 | xen | 4.9.3-r0 | — |
| Alpine v3.6 | xen | 4.8.5-r0 | — |
Advisories 5
- DSA-4274-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1577-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:4300-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3490-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11520-1 xen-4.15.1_01-1.2 on GA media SUSE / openSUSE Security Updates · May 7, 2025