What is CVE-2021-32843?

CVE-2021-32843 is a medium-severity vulnerability in Moby Hyperkit, classified under NULL Pointer Dereference. CVSS score: 6.2/10. Published 2023-02-17.

How severe is CVE-2021-32843?

Medium severity. CVSS v3 base score is 6.2 out of 10.

NULL pointer dereference in Moby Hyperkit

CVE-2021-32843

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of HyperKit, `virtio.c` has is a call to `vc_cfgread` that does not check for null which when called makes the host crash. This issue may lead to a guest crashing the host causing a denial of service. This issue is fixed in commit df0e46c7dbfd81a957d85e449ba41b52f6f7beb4.

Published 2023-02-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (12.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Moby Hyperkit — versions 0.20210107
Mobyproject Hyperkit

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

securitylab.github.com/advisories/GHSL-2021-054_057-moby-hyperkit/ (Third Party Advisory)
github.com/moby/hyperkit/pull/313 (Patch)
github.com/moby/hyperkit/commit/df0e46c7dbfd81a957d85e449ba41b52f6f7beb4 (Patch)

Frequently asked questions

What is CVE-2021-32843?: CVE-2021-32843 is a medium-severity vulnerability in Moby Hyperkit, classified under NULL Pointer Dereference. CVSS score: 6.2/10. Published 2023-02-17.
How severe is CVE-2021-32843?: Medium severity. CVSS v3 base score is 6.2 out of 10.