What is CVE-2017-10921?

CVE-2017-10921 is a critical-severity vulnerability in Xen, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 10.0/10. Published 2017-07-05.

How severe is CVE-2017-10921?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Buffer overflow in Xen

CVE-2017-10921

The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and GNTMAP_host_map mapping, which allows guest OS users to cause a denial of service (count mismanagement and memory corruption) or obtain privileged host OS access, aka XSA-224 bug 2.

Vulnerability class: Buffer Overflow

Published 2017-07-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.025 (84.4th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

security.gentoo.org/glsa/201708-03 (vendor-advisory)
www.debian.org/security/2017/dsa-3969 (vendor-advisory)
www.securitytracker.com/id/1038734 (vdb-entry)
xenbits.xen.org/xsa/advisory-224.html (Patch, Vendor Advisory)
security.gentoo.org/glsa/201710-17 (vendor-advisory)

Frequently asked questions

What is CVE-2017-10921?: CVE-2017-10921 is a critical-severity vulnerability in Xen, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 10.0/10. Published 2017-07-05.
How severe is CVE-2017-10921?: Critical severity. CVSS v3 base score is 10.0 out of 10.