CVE-2021-43619

Memory overwrite via unchecked firmware update length

Published Mar 1, 2022 · Updated Aug 4, 2024

Buffer overflow in Trusted Firmware-M 1.4.x through 1.4.1 allows local users to overwrite RAM via the psa_fwu_write service. The tfm_fwu_write_ipc API reads a caller-supplied block into a local stack buffer without first checking block_size against the buffer limit. Exposure requires the IPC model with the Firmware Update partition enabled and an SPE or NSPE caller; overwritten memory can include SPM data, device drivers, and the partition stack.

CVSS severity7.8
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Buffer overflow in Trusted Firmware-M 1.4.x through 1.4.1 allows local users to overwrite RAM via the psa_fwu_write service. The tfm_fwu_write_ipc API reads a caller-supplied block into a local stack buffer without first checking block_size against the buffer limit. Exposure requires the IPC model with the Firmware Update partition enabled and an SPE or NSPE caller; overwritten memory can include SPM data, device drivers, and the partition stack.

The record

CVE
CVE-2021-43619
Published
Mar 1, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 1, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST National Vulnerability DatabaseAV:L/AC:L/Au:N/C:P/I:P/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.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo