CVE-2021-28701
HIGHDescription
Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 18% of all known CVEs.
References
Related Vulnerabilities
Other CWE-362 (Race Condition) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-6387 | High | 8.1 | 100% | - | Fix |
| CVE-2023-36884 | High | 7.5 | 99% | KEV + Ransom | Fix |
| CVE-2018-15473 | Medium | 5.3 | 99% | - | Fix |
| CVE-2024-27983 | High | 8.2 | 87% | - | Fix |
| CVE-2014-0226 | Medium | 6.8 | 86% | - | Fix |
| CVE-2016-5195 | High | 7.0 | 84% | KEV | Fix |
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Markdown
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.