Vulnerability · Published Jun 30, 2021 · Assigned by XEN
CVE-2021-28692
High 7.1
In plain English
A high-severity security flaw in xen from Xen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
inappropriate x86 IOMMU timeout detection / handling IOMMUs process commands issued to them in parallel with the operation of the CPU(s) issuing such commands. In the current implementation in Xen, asynchronous notification of the completion of such commands is not used. Instead, the issuing CPU spin-waits for the completion of the most recently issued command(s). Some of these waiting loops try to apply a timeout to fail overly-slow commands. The course of action upon a perceived timeout actually being detected is inappropriate: - on Intel hardware guests which did not originally cause the timeout may be marked as crashed, - on AMD hardware higher layer callers would not be notified of the issue, making them continue as if the IOMMU operation succeeded.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.15.0-r1 | ALPINE-CVE-2021-28692 |
| Alpine:v3.21 | xen | 4.15.0-r1 | ALPINE-CVE-2021-28692 |
| Alpine:v3.22 | xen | 4.15.0-r1 | ALPINE-CVE-2021-28692 |
| Alpine:v3.23 | xen | 4.15.0-r1 | ALPINE-CVE-2021-28692 |
| Alpine:v3.24 | xen | 4.15.0-r1 | ALPINE-CVE-2021-28692 |
| Debian:12 | xen | 4.14.2+25-gb6a8c4f72d-1 | DEBIAN-CVE-2021-28692 |
| Debian:13 | xen | 4.14.2+25-gb6a8c4f72d-1 | DEBIAN-CVE-2021-28692 |
| Debian:14 | xen | 4.14.2+25-gb6a8c4f72d-1 | DEBIAN-CVE-2021-28692 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28692 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28692 |
| Ubuntu:25.10 | xen | no fix listed | UBUNTU-CVE-2021-28692 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28692 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2021-28692 |
Affected products (as reported)
References
- https://xenbits.xenproject.org/xsa/advisory-373.txt x_refsource_MISC
- GLSA-202107-30 vendor-advisory, x_refsource_GENTOO