VDB
CVE-2021-28701
CVE-2021-28701
PUBLISHED
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.
EPSS 0.06% · 18.9th percentile
Risk Scores
EPSS Score
0.06%
18.9th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:24.04:LTS | xen | 4.17.2-1, 4.17.2+76-ge1f9cb16e2-1ubuntu1, 4.17.2+76-ge1f9cb16e2-1 |
| Ubuntu:18.04:LTS | xen | 4.9.0-0ubuntu4, 4.9.2-0ubuntu1, 4.9.0-0ubuntu3 |
| Ubuntu:20.04:LTS | xen | 4.11.3+24-g14b62ab3e5-1ubuntu2.3, 0, 4.9.2-0ubuntu2 |
| Ubuntu:25.10 | xen | *, 0, 4.20.0-1ubuntu1 |
| Ubuntu:16.04:LTS | xen | 4.6.0-1ubuntu4, 4.6.5-0ubuntu1.2, 4.6.5-0ubuntu1 |
| Ubuntu:22.04:LTS | xen | 4.16.0-1~ubuntu2.1, 4.11.4+24-gddaaccbbab-1ubuntu2, 0 |
Timeline
- Sep 8, 2021 CVE Published
- Sep 9, 2021 EPSS Score
- Sep 18, 2021 EPSS Score
- Sep 25, 2021 EPSS Score
- Oct 9, 2021 EPSS Score
- Nov 6, 2021 EPSS Score
- Jan 2, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Mar 1, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- Apr 28, 2022 EPSS Score
- Aug 22, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2021-28701 third-party-advisory
- https://xenbits.xen.org/xsa/advisory-384.html third-party-advisory
- https://xenbits.xenproject.org/xsa/advisory-384.txt third-party-advisory
- http://xenbits.xen.org/xsa/advisory-384.html third-party-advisory
- http://www.openwall.com/lists/oss-security/2021/09/08/2 third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-28701 third-party-advisory