SARA / Free Tools / CVE / CVE-2023-5909

CVE-2023-5909 — KEPServerEX does not properly validate certificates from clients which may allow

KEPServerEX does not properly validate certificates from clients which may allow unauthenticated users to connect.

CVSS

7.5 HIGH

EPSS

0.08% (top 77.30%)

CWE

CWE-297

Published

2023-11-30T22:05:59.595Z

Last modified

2026-02-25T17:20:07.195Z

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

01What is this vulnerability?

KEPServerEX does not properly validate certificates from clients which may allow unauthenticated users to connect.

Vendor	Product	Versions
PTC	KEPServerEX	0
PTC	ThingWorx Kepware Server	0
PTC	ThingWorx Industrial Connectivity	All versions
PTC	OPC	Aggregator — 0
PTC	ThingWorx Kepware Edge	0
Rockwell Automation	KEPServer Enterprise	0
GE Gigital	Industrial Gateway Server	0
Software Toolbox	TOP Server	0

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

Patch to a fixed version listed in the vendor advisory (see references below).
Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
Hunt historical logs for exploitation indicators — see Detection signatures below.

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

Want this in your SOAR or SIEM?
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