CVE-2021-32845: moby hyperkit Use of Uninitialized Resource

Vulnerability summary

CVE-2021-32845 is a high (CVSS 7.8) Use of Uninitialized Resource vulnerability in moby hyperkit. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.3% of scored vulnerabilities.

Timeline

1. 17-02-2023
   PublishedVulnerability first disclosed.
2. 10-03-2025
   Last modifiedVulnerability information updated.

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.

• CWE-908Use of Uninitialized ResourceThe product uses or accesses a resource that has not been initialized.
• CWE-252Unchecked Return ValueThe product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.