CVE-2023-5397Network attack vector

Remote code execution via malformed connection message

Published Apr 17, 2024 · Updated Aug 8, 2024

Improper input validation in Honeywell Experion Server allows remote attackers to execute code via a malformed connection message. The server accepts the message while creating a connection, but Honeywell has not disclosed the parsing locus or validation error. No authentication or user interaction is required; successful exploitation can execute code or crash the server, and attack complexity is high.

CVSS severity8.1
High
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Honeywell Experion Server allows remote attackers to execute code via a malformed connection message. The server accepts the message while creating a connection, but Honeywell has not disclosed the parsing locus or validation error. No authentication or user interaction is required; successful exploitation can execute code or crash the server, and attack complexity is high.

The record

CVE
CVE-2023-5397
Published
Apr 17, 2024
Updated
Aug 8, 2024
Vendor
Honeywell Technologies
Product
Experion Server
Classifications
CWE-20, CAPEC-153, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 8, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=510.1 <=510.2_hf13
  2. Affected versionversion=510.1 <=510.2 HF13
  3. Affected versionversion=511.1 <=511.5_tcu4_hf3
  4. Affected versionversion=511.1 <=511.5 TCU4 HF3
  5. Affected versionversion=520.1 <=520.1_tcu4
  6. Affected versionversion=520.1 <=520.1 TCU4
  7. Affected versionversion=520.2 <=520.2_tcu4
  8. Affected versionversion=520.2 <=520.2 TCU4
  9. Affected versionversion=520.2_tcu4_hfr2 <=511.5_tcu4_hf3
  10. Affected versionversion=520.2 TCU4 HFR2 <=511.5 TCU4 HF3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Honeywell Technologies · Experion Serverversion=510.1 <=510.2_hf13; version=510.1 <=510.2 HF13; version=511.1 <=511.5_tcu4_hf3; version=511.1 <=511.5 TCU4 HF3; version=520.1 <=520.1_tcu4; version=520.1 <=520.1 TCU4; version=520.2 <=520.2_tcu4; version=520.2 <=520.2 TCU4; version=520.2_tcu4_hfr2 <=511.5_tcu4_hf3; version=520.2 TCU4 HFR2 <=511.5 TCU4 HF3

Published CVSS scores

8.1Honeywell International Inc.CVSS:3.1/AV:N/AC:H/PR:N/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.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CAPEC-153Input Data Manipulation
T1210Exploitation of Remote Services

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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