Denial of service via unchecked packet subtraction
Published Jul 10, 2025 · Updated Aug 4, 2025
Integer underflow in Honeywell Experion PKS 520.1 through 520.2 TCU9 and 530 through 530 TCU3 allows remote attackers to cause a denial of service. The CDA FTEB responder subtracts values while processing short network packets without properly checking the resulting integer value. No authentication or user interaction is required; crafted network input can manipulate data and interrupt affected controller operations.
Summary
What happened
Integer underflow in Honeywell Experion PKS 520.1 through 520.2 TCU9 and 530 through 530 TCU3 allows remote attackers to cause a denial of service. The CDA FTEB responder subtracts values while processing short network packets without properly checking the resulting integer value. No authentication or user interaction is required; crafted network input can manipulate data and interrupt affected controller operations.
The record
- CVE
- CVE-2025-3947
- Published
- Jul 10, 2025
- Updated
- Aug 4, 2025
- Vendor
- Honeywell Technologies
- Product
- C200E
- Classifications
- CWE-191, CAPEC-153, T0814
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 10, 2025CVE publishedPublication date reported by the CVE source.
- Aug 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=520.1 <=520.2 TCU9
- Affected versionversion=530 <=530 TCU3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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