Unauthenticated permanent DoS via crafted TCP packets
Published Oct 11, 2022 · Updated Jun 2, 2026
Improper input validation in Siemens SIMATIC HMI panels before V17 Update 4 or Update 5 allows remote attackers to cause permanent denial of service via TCP packets. Certain TCP services accept malformed input without proper validation, leaving the panel in a state that requires reboot. The attack is unauthenticated and network reachable; impact is service interruption only, with no evidence of data disclosure or modification.
Summary
What happened
Improper input validation in Siemens SIMATIC HMI panels before V17 Update 4 or Update 5 allows remote attackers to cause permanent denial of service via TCP packets. Certain TCP services accept malformed input without proper validation, leaving the panel in a state that requires reboot. The attack is unauthenticated and network reachable; impact is service interruption only, with no evidence of data disclosure or modification.
The record
- CVE
- CVE-2022-40227
- Published
- Oct 11, 2022
- Updated
- Jun 2, 2026
- Vendor
- Siemens
- Product
- SIMATIC HMI KTP900 Basic
- Classifications
- CWE-20, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 11, 2022CVE publishedPublication date reported by the CVE source.
- Jun 2, 2026Record 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=All versions < V17 Update 5
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.
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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