CVE-2018-7833 — An Improper Check for Unusual or Exceptional Conditions vulnerability exists in

An Improper Check for Unusual or Exceptional Conditions vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where an unauthenticated user can send a specially crafted XML data via a POST request to cause the web server to bec

01What is this vulnerability?

An Improper Check for Unusual or Exceptional Conditions vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where an unauthenticated user can send a specially crafted XML data via a POST request to cause the web server to become unavailable

02Affected products

Vendor	Product	Versions
Schneider Electric SE	Embedded Web Servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200	Embedded Web Servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200

03Active exploitation status

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

04Recommended remediation

• 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.

05Technical details

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

06Detection signatures

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

07Related CVEs

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

08Timeline

• Published: 2018-12-17T22:00:00.000Z
• Last modified: 2024-08-05T06:37:59.565Z

09References

• www.schneider-electric.com — https://www.schneider-electric.com/en/download/document/SEVD-2018-327-01/