CVE-2021-36979

Host-process crash via tb_flush_armeb out-of-bounds write

Published Jul 20, 2021 · Updated Aug 4, 2024

Out-of-bounds write in tb_flush_armeb in Unicorn Engine 1.0.2 allows local users to crash the host via crafted ARM big-endian code. The execution path writes outside its destination buffer during ARM big-endian emulation, but public records do not identify the faulty index or size calculation. Triggering requires user interaction with crafted emulated code, and the documented consequence is a host-process crash rather than data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.88%
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 tb_flush_armeb in Unicorn Engine 1.0.2 allows local users to crash the host via crafted ARM big-endian code. The execution path writes outside its destination buffer during ARM big-endian emulation, but public records do not identify the faulty index or size calculation. Triggering requires user interaction with crafted emulated code, and the documented consequence is a host-process crash rather than data disclosure or modification.

The record

CVE
CVE-2021-36979
Published
Jul 20, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
local
Privileges
unauthenticated

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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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