What’s Vulnerable › Vulnerabilities
CVE-2021-3750
- Severity: high (CVSS 8.2 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2022-05-02 · updated 2026-06-17
- Weakness: CWE-416
Description
A DMA reentrancy issue was found in the USB EHCI controller emulation of QEMU. EHCI does not verify if the Buffer Pointer overlaps with its MMIO region when it transfers the USB packets. Crafted content may be written to the controller's registers and trigger undesirable actions (such as reset) while the device is still transferring packets. This can ultimately lead 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 execute arbitrary code within the context of the QEMU process on the host. This flaw affects QEMU versions before 7.0.0.
Affected products
- QEMU: before 7.0.0 — fixed in 7.0.0
- Red Hat Enterprise Linux: 8.0
How to fix
Upgrade to a fixed version: QEMU 7.0.0. Check the vendor advisory for mitigations.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1999073
- https://gitlab.com/qemu-project/qemu/-/issues/541
- https://gitlab.com/qemu-project/qemu/-/issues/556
- https://security.gentoo.org/glsa/202208-27
- https://security.netapp.com/advisory/ntap-20220624-0003/
- https://bugzilla.redhat.com/show_bug.cgi?id=1999073
- https://gitlab.com/qemu-project/qemu/-/issues/541
- https://gitlab.com/qemu-project/qemu/-/issues/556
- https://security.gentoo.org/glsa/202208-27
- https://security.netapp.com/advisory/ntap-20220624-0003/
Get alerted when CVE-2021-3750 or the next vulnerability affects your stack