Use After Free in Qemu
CVE-2021-3929
A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition or, potentially, executing arbitrary code within the context of the QEMU process on the host.
Vulnerability class: Use-After-Free
EPSS: 0.006 (47.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Qemu
- Fedoraproject Fedora — versions 35, 36
- N/a Qemu — versions Fixed in qemu-kvm 7.0.0-rc0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- secalert@redhat.com (Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (Exploit, Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (x_refsource_FEDORA, vendor-advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2021-3929?
- CVE-2021-3929 is a high-severity vulnerability in Qemu, classified under Use After Free. CVSS score: 8.2/10. Published 2022-08-25.
- How severe is CVE-2021-3929?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2021-3929 known to be exploited?
- 14 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.