Vulnerability in Moby Hyperkit
CVE-2021-32846
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.
EPSS: 0.003 (24.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
Affected products
- Moby Hyperkit — versions 0.20210107
- Mobyproject Hyperkit
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (Third Party Advisory)
- security-advisories@github.com (Patch)
- security-advisories@github.com (Patch)
Frequently asked questions
- What is CVE-2021-32846?
- CVE-2021-32846 is a high-severity vulnerability in Moby Hyperkit, classified under Use of Uninitialized Resource. CVSS score: 7.7/10. Published 2023-02-17.
- How severe is CVE-2021-32846?
- High severity. CVSS v3 base score is 7.7 out of 10.
- Is CVE-2021-32846 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.