Vulnerability · Published Nov 24, 2021 · Assigned by XEN
CVE-2021-28706
High 8.6
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 2.2% (higher than 83% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It would then only be the overflowed (and hence small) number which gets compared against the established upper bound.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | xen | 4.14.3+32-g9de3671772-1 | DEBIAN-CVE-2021-28706 |
| Debian:13 | xen | 4.14.3+32-g9de3671772-1 | DEBIAN-CVE-2021-28706 |
| Debian:14 | xen | 4.14.3+32-g9de3671772-1 | DEBIAN-CVE-2021-28706 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28706 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28706 |
| Ubuntu:25.10 | xen | no fix listed | UBUNTU-CVE-2021-28706 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2021-28706 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2021-28706 |
Affected products (as reported)
References
- https://xenbits.xenproject.org/xsa/advisory-385.txt
- FEDORA-2021-03645e9807 vendor-advisory
- DSA-5017 vendor-advisory
- FEDORA-2021-2b3a2de94f vendor-advisory
- GLSA-202402-07 vendor-advisory