CVE-2020-35506Public exploit

Host process crash via freed DMA state

Published May 28, 2021 · Updated Aug 4, 2024

Use-after-free in QEMU before 6.0.0 allows privileged guest OS users to crash the host QEMU process through an am53c974 CMD_TI command. The esp_do_dma path accesses freed request-backed state while completing the Information Transfer DMA operation. Control of the emulated controller from a privileged guest is required; successful abuse can also execute code with the QEMU process's privileges.

CVSS severity5.0
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in QEMU before 6.0.0 allows privileged guest OS users to crash the host QEMU process through an am53c974 CMD_TI command. The esp_do_dma path accesses freed request-backed state while completing the Information Transfer DMA operation. Control of the emulated controller from a privileged guest is required; successful abuse can also execute code with the QEMU process's privileges.

The record

CVE
CVE-2020-35506
Published
May 28, 2021
Updated
Aug 4, 2024
Vendor
QEMU Project
Product
QEMU
Classifications
CWE-416, T1611
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 6.0.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

QEMU Project · QEMUversion=qemu 6.0.0

Published CVSS scores

5.0Red HatCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:L
6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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.

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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 exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1611Escape to Host

Public exploit references

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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