Vulnerability Details : CVE-2021-28701
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.
Products affected by CVE-2021-28701
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
- cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-28701
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 8 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-28701
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
4.4
|
MEDIUM | AV:L/AC:M/Au:N/C:P/I:P/A:P |
3.4
|
6.4
|
NIST | |
|
7.8
|
HIGH | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
1.1
|
6.0
|
NIST |
CWE ids for CVE-2021-28701
-
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-28701
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CEHZLIR5DFYYQBH55AERWHLO54OFU42C/
[SECURITY] Fedora 33 Update: xen-4.14.2-4.fc33 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://xenbits.xenproject.org/xsa/advisory-384.txt
Vendor Advisory
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3HEHUIUWSSMCQGQY3GWX4J2SZGYP5W2Z/
[SECURITY] Fedora 35 Update: xen-4.15.0-7.fc35 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://security.gentoo.org/glsa/202208-23
Xen: Multiple Vulnerabilities (GLSA 202208-23) — Gentoo securityThird Party Advisory
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L4MI3MQAPGILCLXBGQWPZHGE3ALSO4ZU/
[SECURITY] Fedora 34 Update: xen-4.14.2-4.fc34 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://www.debian.org/security/2021/dsa-4977
Debian -- Security Information -- DSA-4977-1 xenThird Party Advisory
-
http://www.openwall.com/lists/oss-security/2021/09/08/2
oss-security - Xen Security Advisory 384 v3 (CVE-2021-28701) - Another race in XENMAPSPACE_grant_table handlingMailing List;Third Party Advisory
-
http://xenbits.xen.org/xsa/advisory-384.html
XSA-384 - Xen Security AdvisoriesVendor Advisory
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