Resource exhaustion in Qemu

CVE-2021-3735

A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while handling a host-to-device Register FIS (Frame Information Structure) packet from the guest. A privileged user inside the guest could use this flaw to hang the QEMU process on the host, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-3735: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Qemu — versions 6.1.0
  • Debian Linux — versions 10.0, 11.0
  • Qemu — versions Not Known

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-3735?
CVE-2021-3735 is a medium-severity vulnerability in Qemu, classified under Improper Locking. CVSS score: 4.4/10. Published 2022-08-26.
How severe is CVE-2021-3735?
Medium severity. CVSS v3 base score is 4.4 out of 10.