CVE-2021-3582

Host process crash via unchecked remap boundaries

Published Mar 25, 2022 · Updated Aug 3, 2024

Memory-remapping flaw in QEMU 2.17.2 allows guest OS users to crash the host QEMU process using a crafted PVRDMA command. In hw/rdma/vmw/pvrdma_cmd.c, pvrdma_map_to_pdir() repeatedly uses MREMAP_FIXED without verifying that guest-supplied nchunks matches the rounded mapping length, so a remap can extend past the allocated region. Exploitation requires control of a guest configured with the VMware paravirtual RDMA device and interrupts that guest's host-side emulator process.

CVSS severity6.5
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-remapping flaw in QEMU 2.17.2 allows guest OS users to crash the host QEMU process using a crafted PVRDMA command. In hw/rdma/vmw/pvrdma_cmd.c, pvrdma_map_to_pdir() repeatedly uses MREMAP_FIXED without verifying that guest-supplied nchunks matches the rounded mapping length, so a remap can extend past the allocated region. Exploitation requires control of a guest configured with the VMware paravirtual RDMA device and interrupts that guest's host-side emulator process.

The record

CVE
CVE-2021-3582
Published
Mar 25, 2022
Updated
Aug 3, 2024
Vendor
QEMU Project
Product
QEMU
Classifications
CWE-119, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 25, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=qemu 2.17.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

QEMU Project · QEMUversion=qemu 2.17.2

Published CVSS scores

6.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
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

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Your stack

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