CVE-2021-44149

Local TrustZone bypass via CSU misconfiguration

Published Dec 7, 2021 · Updated Aug 4, 2024

Improper access control in OP-TEE Trusted OS through 3.15.0 allows local users to bypass TrustZone and read or write Secure World memory. The OPTEE-OS CSU driver leaves security access configuration incomplete for wakeup-related registers on NXP i.MX6UL devices, allowing NonSecure World peripherals to perform arbitrary Secure World memory operations. Exploitation requires execution in the NonSecure World on an affected i.MX6UL system and can fully compromise the Trusted Execution Environment.

CVSS severity7.8
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in OP-TEE Trusted OS through 3.15.0 allows local users to bypass TrustZone and read or write Secure World memory. The OPTEE-OS CSU driver leaves security access configuration incomplete for wakeup-related registers on NXP i.MX6UL devices, allowing NonSecure World peripherals to perform arbitrary Secure World memory operations. Exploitation requires execution in the NonSecure World on an affected i.MX6UL system and can fully compromise the Trusted Execution Environment.

The record

CVE
CVE-2021-44149
Published
Dec 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 7, 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

4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

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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