{"id":"ALPINE-CVE-2021-28701","details":"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.","modified":"2026-08-27T22:18:01.577749443Z","published":"2021-09-08T14:15:08.547Z","upstream":["CVE-2021-28701"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-28701"}],"affected":[{"package":{"name":"xen","ecosystem":"Alpine:v3.11","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.13.3-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.12","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.13.3-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.13","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.14.2-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.15.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-28701.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H"}]}