Skip to content
Fencer Vulns
high 7.1

CVE-2021-32847 json

Moby HyperKit uninitialized memory use in virtio-sock pci_vtsock_proc_tx

published 2023-02-20 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19579

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior, a malicious guest can trigger a vulnerability in the host by abusing the disk driver that may lead to the disclosure of the host memory into the virtualized guest. This issue is fixed in commit cf60095a4d8c3cb2e182a14415467afd356e982f.

Patch / fix

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
19 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • securitylab.github.com https://securitylab.github.com/advisories/GHSL-2021-058-moby-hyperkit/ referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/moby/hyperkit/blob/2f061e447e1435cdf1b9eda364cea6414f2c606b/src/lib/pci_virtio_block.c#L316 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
NVD 3.1 6.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Affected products

  • moby hyperkit

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.