Log in Start free

Vulnerability · Published Aug 25, 2022 · Assigned by redhat

CVE-2021-3929

High 8.2

In plain English

A high-severity use-after-free in QEMU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.2High
Exploit odds (30 days)0.7%top 47.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12qemu1:7.0+dfsg-1DEBIAN-CVE-2021-3929
Debian:13qemu1:7.0+dfsg-1DEBIAN-CVE-2021-3929
Debian:14qemu1:7.0+dfsg-1DEBIAN-CVE-2021-3929
Ubuntu:22.04:LTSqemu1:6.2+dfsg-2ubuntu6.2USN-5489-1
Ubuntu:22.04:LTSqemu1:6.2+dfsg-2ubuntu6.2UBUNTU-CVE-2021-3929

Affected products (as reported)

VendorProductVersions
n/a QEMU Fixed in qemu-kvm 7.0.0-rc0

Weakness: CWE-416

References