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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.022 (82.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.021 · newest: 0.022 · change: +0.002
Affected products
- Xen — versions 4.12.x, unspecified, 4.14.x
- Debian Linux — versions 11.0
- Fedoraproject Fedora — versions 34, 35
Weakness classification (CWE)
References
- xenbits.xenproject.org/xsa/advisory-385.txt (Patch, Third Party Advisory, Mitigation)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.debian.org/security/2021/dsa-5017 (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202402-07 (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.