CVE-2021-32846

Moby HyperKit uninitialized memory use in virtio-sock pci_vtsock_proc_tx

Description

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107, function `pci_vtsock_proc_tx` in `virtio-sock` can lead to to uninitialized memory use. In this situation, there is a check for the return value to be less or equal to `VTSOCK_MAXSEGS`, but that check is not sufficient because the function can return `-1` if it finds an error it cannot recover from. Moreover, the negative return value will be used by `iovec_pull` in a while condition that can further lead to more corruption because the function is not designed to handle a negative `iov_len`. This issue may lead to a guest crashing the host causing a denial of service and, under certain circumstance, memory corruption. This issue is fixed in commit af5eba2360a7351c08dfd9767d9be863a50ebaba.

Categories

7.7
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.03%
Third-Party Advisory github.com
Affected: moby hyperkit
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-32846?
CVE-2021-32846 has been scored as a high severity vulnerability.
How to fix CVE-2021-32846?
To fix CVE-2021-32846, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-32846 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-32846 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-32846?
CVE-2021-32846 affects moby hyperkit.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.