CVE-2020-14394Public exploit

Host process hang via guest-controlled TRB loop

Published Aug 17, 2022 · Updated Aug 4, 2024

An infinite loop in QEMU 6.1.50 xHCI emulation allows privileged guest OS users to hang the host QEMU process via crafted TRBs. The xhci_ring_chain_length() function in hw/usb/hcd-xhci.c keeps fetching empty TRBs while its exit conditions depend entirely on guest-controlled values. Exploitation requires control inside a guest with an emulated xHCI device and interrupts that guest's QEMU process without reported data access or modification.

CVSS severity3.2
Low
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

An infinite loop in QEMU 6.1.50 xHCI emulation allows privileged guest OS users to hang the host QEMU process via crafted TRBs. The xhci_ring_chain_length() function in hw/usb/hcd-xhci.c keeps fetching empty TRBs while its exit conditions depend entirely on guest-controlled values. Exploitation requires control inside a guest with an emulated xHCI device and interrupts that guest's QEMU process without reported data access or modification.

The record

CVE
CVE-2020-14394
Published
Aug 17, 2022
Updated
Aug 4, 2024
Vendor
QEMU Project
Product
QEMU
Classifications
CWE-835, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Aug 17, 2022CVE 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 6.1.50

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

QEMU Project · QEMUversion=QEMU 6.1.50

Published CVSS scores

3.2NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L

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-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

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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