CVE-2018-4850 — A vulnerability has been identified in SIMATIC S7-400 (incl

A vulnerability has been identified in SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below (All versions), SIMATIC S7-400 (incl. F) CPU hardware version 5.0 (All firmware versions < V5.2), SIMATIC S7-400H CPU hardware version 4.5 and below (All versions). The affected

01What is this vulnerability?

A vulnerability has been identified in SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below (All versions), SIMATIC S7-400 (incl. F) CPU hardware version 5.0 (All firmware versions < V5.2), SIMATIC S7-400H CPU hardware version 4.5 and below (All versions). The affected CPUs improperly validate S7 communication packets which could cause a Denial-of-Service condition of the CPU. The CPU will…

02Affected products

Vendor	Product	Versions
Siemens AG	SIMATIC S7	400 (incl. F) CPU hardware version 4.0 and below, SIMATIC S7-400 (incl. F) CPU hardware version 5.0, SIMATIC S7-400H CPU hardware version 4.5 and below — SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below : All versions, SIMATIC S7-400 (incl. F) CPU hardware version 5.0 : All firmware versions < V5.2, SIMATIC S7-400H CPU hardware version 4.5 and below : All versions

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: 2018-05-16T17:00:00.000Z
• Last modified: 2024-09-16T22:46:02.128Z

09References

• cert-portal.siemens.com — https://cert-portal.siemens.com/productcert/pdf/ssa-914382.pdf
• www.securityfocus.com — http://www.securityfocus.com/bid/104217
• www.siemens.com — https://www.siemens.com/global/en/home/products/services/cert.html#SecurityPubli…