{"cve":"CVE-2021-32846","nvd":{"published":"2023-02-17T23:15:12.037","modified":"2026-06-17T03:53:44.990","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-754","CWE-908"],"references":["https://github.com/moby/hyperkit/commit/af5eba2360a7351c08dfd9767d9be863a50ebaba","https://github.com/moby/hyperkit/pull/313","https://securitylab.github.com/advisories/GHSL-2021-054_057-moby-hyperkit/","https://github.com/moby/hyperkit/commit/af5eba2360a7351c08dfd9767d9be863a50ebaba","https://github.com/moby/hyperkit/pull/313"],"products":["mobyproject:hyperkit"],"source":"nvd","synced_at":"2026-10-19T21:37:38.595364862+00:00"},"epss":{"cve":"CVE-2021-32846","score":0.00317,"percentile":0.2469,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}