CVE-2021-3608

Host process crash via uninitialized PVRDMA pointer

Published Feb 24, 2022 · Updated Aug 3, 2024

Uninitialized-pointer access in QEMU before 6.1.0 allows privileged guest OS users to crash the host QEMU process via a PVRDMA register write. In pvrdma_ring_init(), improper initialization of ring->pages can pass an uninitialized pointer to rdma_pci_dma_unmap() while handling PVRDMA_REG_DSRHIGH. The path requires high privileges inside a guest configured with the paravirtual RDMA device, and its bounded impact is interruption of that guest's host process.

CVSS severity6.0
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Uninitialized-pointer access in QEMU before 6.1.0 allows privileged guest OS users to crash the host QEMU process via a PVRDMA register write. In pvrdma_ring_init(), improper initialization of ring->pages can pass an uninitialized pointer to rdma_pci_dma_unmap() while handling PVRDMA_REG_DSRHIGH. The path requires high privileges inside a guest configured with the paravirtual RDMA device, and its bounded impact is interruption of that guest's host process.

The record

CVE
CVE-2021-3608
Published
Feb 24, 2022
Updated
Aug 3, 2024
Vendor
QEMU Project
Product
QEMU
Classifications
CWE-824, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=qemu-kvm 6.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

QEMU Project · QEMUversion=qemu-kvm 6.1.0

Published CVSS scores

6.0NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-824Access of Uninitialized Pointer
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo