Resource exhaustion in Xen
CVE-2021-28706
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.
EPSS: 0.021 (79.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Xen — versions 4.12.x, unspecified, 4.14.x
- Debian Debian_linux — versions 11.0
- Fedoraproject Fedora — versions 34, 35
Weakness classification (CWE)
References
- security@xen.org (Patch, Third Party Advisory, Mitigation)
- security@xen.org (vendor-advisory)
- security@xen.org (vendor-advisory, Third Party Advisory)
- security@xen.org (vendor-advisory)
- security@xen.org (vendor-advisory)
Frequently asked questions
- What is CVE-2021-28706?
- CVE-2021-28706 is a high-severity vulnerability in Xen, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 8.6/10. Published 2021-11-24.
- How severe is CVE-2021-28706?
- High severity. CVSS v3 base score is 8.6 out of 10.