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CVE Record

CVE-2020-27661: A divide-by-zero issue was found in dwc2_handle_packet in hw/usb/hcd-dwc2.c in the hcd-dwc2 USB host contro...

A divide-by-zero issue was found in dwc2_handle_packet in hw/usb/hcd-dwc2.c in the hcd-dwc2 USB host controller emulation of QEMU. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A malicious virtual machine guest could crash its QEMU process on the host by triggering a divide-by-zero bug in USB host-controller emulation. The documented impact is denial of service, not data theft or code execution.

Executive priority

Treat as a virtualization availability risk. Prioritize shared, multi-tenant, lab, and service-provider environments where one guest crash could affect customer service commitments or operational reliability.

Technical view

CVE-2020-27661 affects QEMU hcd-dwc2 USB host controller emulation in hw/usb/hcd-dwc2.c, specifically dwc2_handle_packet. The flaw is described as divide-by-zero reachable from a malicious guest, causing the host QEMU process to crash.

Likely exposure

Exposure is most likely where QEMU runs untrusted or semi-trusted guests with hcd-dwc2 USB host controller emulation enabled or available. The source bundle does not identify exact affected versions or products beyond QEMU and downstream vendor references.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. Attack context appears guest-to-host denial of service: a malicious guest crashes its QEMU process, potentially disrupting that VM and related service availability.

Researcher notes

Evidence supports guest-triggered QEMU process denial of service. The bundle lacks CVSS, CWE, exact affected versions, and detailed downstream product matrices, so validation should rely on vendor package advisories and the referenced upstream commit.

Mitigation direction

  • Check QEMU, OS, and appliance vendor guidance for CVE-2020-27661 fixes.
  • Update QEMU or downstream virtualization packages to patched builds.
  • Disable unused hcd-dwc2 USB emulation where operationally feasible.
  • Avoid placing untrusted guests on hosts lacking vendor fixes.
  • Review NetApp guidance if using affected NetApp products.

Validation and detection

  • Inventory QEMU deployments and downstream appliances using QEMU virtualization.
  • Check VM configurations for hcd-dwc2 USB controller emulation.
  • Confirm installed packages include the referenced QEMU fix or vendor backport.
  • Review host logs for unexpected QEMU process crashes.
  • Document guest trust boundaries and shared-host impact.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2020-27661 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
6Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.