CVE-2020-36431

Local denial of service via helper_wfe_arm write

Published Jul 20, 2021 · Updated Aug 4, 2024

Out-of-bounds write in Unicorn Engine 1.0.2 allows local users to cause a service interrupt via the helper_wfe_arm ARM emulation helper. The helper performs an out-of-bounds memory write while processing ARM WFE behavior, corrupting emulator state and potentially crashing the hosting process. Exploitation requires local low-privilege access to execute code through Unicorn; no remote exposure or confidentiality impact is documented.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Unicorn Engine 1.0.2 allows local users to cause a service interrupt via the helper_wfe_arm ARM emulation helper. The helper performs an out-of-bounds memory write while processing ARM WFE behavior, corrupting emulator state and potentially crashing the hosting process. Exploitation requires local low-privilege access to execute code through Unicorn; no remote exposure or confidentiality impact is documented.

The record

CVE
CVE-2020-36431
Published
Jul 20, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1203
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

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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