Vulnerability · Published Aug 27, 2021 · Assigned by XEN

CVE-2021-28699

Medium 5.5

In plain English

A medium-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 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.4%top 70.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

inadequate grant-v2 status frames array bounds check The v2 grant table interface separates grant attributes from grant status. That is, when operating in this mode, a guest has two tables. As a result, guests also need to be able to retrieve the addresses that the new status tracking table can be accessed through. For 32-bit guests on x86, translation of requests has to occur because the interface structure layouts commonly differ between 32- and 64-bit. The translation of the request to obtain the frame numbers of the grant status table involves translating the resulting array of frame numbers. Since the space used to carry out the translation is limited, the translation layer tells the core function the capacity of the array within translation space. Unfortunately the core function then only enforces array bounds to be below 8 times the specified value, and would write past the available space if enough frame numbers needed storing.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20xen4.15.0-r2ALPINE-CVE-2021-28699
Alpine:v3.21xen4.15.0-r2ALPINE-CVE-2021-28699
Alpine:v3.22xen4.15.0-r2ALPINE-CVE-2021-28699
Alpine:v3.23xen4.15.0-r2ALPINE-CVE-2021-28699
Alpine:v3.24xen4.15.0-r2ALPINE-CVE-2021-28699
Debian:12xen4.14.3-1DEBIAN-CVE-2021-28699
Debian:13xen4.14.3-1DEBIAN-CVE-2021-28699
Debian:14xen4.14.3-1DEBIAN-CVE-2021-28699
Ubuntu:22.04:LTSxenno fix listedUBUNTU-CVE-2021-28699
Ubuntu:24.04:LTSxenno fix listedUBUNTU-CVE-2021-28699
Ubuntu:25.10xenno fix listedUBUNTU-CVE-2021-28699
Ubuntu:26.04:LTSxenno fix listedUBUNTU-CVE-2021-28699
Ubuntu:26.10xenno fix listedUBUNTU-CVE-2021-28699

Affected products (as reported)

VendorProductVersions
Xen xen 4.11.x – before unspecified

References