How severe is CVE-2021-32845?

CVE-2021-32845 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-32845 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-32845?

CVE-2021-32845 affects Mobyproject Hyperkit. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-32845?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-32845 published?

CVE-2021-32845 was published on 2023-02-17 and last updated on 2026-06-17.

CVE-2021-32845

CVE-2021-32845 is a high-severity vulnerability in Mobyproject Hyperkit with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-252.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-252
Affected product: Mobyproject Hyperkit
Published: 2023-02-17
Last modified: 2026-06-17

Description

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of HyperKit, the implementation of `qnotify` at `pci_vtrnd_notify` fails to check the return value of `vq_getchain`. This leads to `struct iovec iov;` being uninitialized and used to read memory in `len = (int) read(sc->vrsc_fd, iov.iov_base, iov.iov_len);` when an attacker is able to make `vq_getchain` fail. 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 41272a980197917df8e58ff90642d14dec8fe948.

Frequently asked questions

What is CVE-2021-32845?: HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of HyperKit, the implementation of `qnotify` at `pci_vtrnd_notify` fails to check the return value of `vq_getchain`. This leads to `struct iovec iov;` being uninitialized and used to read memory in `len = (int) read(sc->vrsc_fd, iov.iov_base, iov.iov_len);` when an attacker is able to make `vq_getchain` fail. 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 41272a980197917df8e58ff90642d14dec8fe948.
How severe is CVE-2021-32845?: CVE-2021-32845 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-32845 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-32845?: CVE-2021-32845 affects Mobyproject Hyperkit. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-32845?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-32845 published?: CVE-2021-32845 was published on 2023-02-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mobyproject:hyperkit:*:*:*:*:*:*:*:*

More vulnerabilities in Mobyproject Hyperkit

CVE-2021-32846 — High (CVSS 7.7): HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107, function…
CVE-2021-32847 — High (CVSS 7.1): HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior, a…
CVE-2021-32844 — Medium (CVSS 6.2): HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of…
CVE-2021-32843 — Medium (CVSS 6.2): HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of…

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