Skip to content
Fencer Vulns
medium 6.5

CVE-2020-15791 json

A vulnerability has been identified in SIMATIC S7-300 CPU family (incl.

published 2020-09-09 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7774

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

A vulnerability has been identified in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions), SIMATIC S7-400 CPU family (incl. SIPLUS variants) (All versions), SIMATIC WinAC RTX (F) 2010 (All versions), SINUMERIK 840D sl (All versions). The authentication protocol between a client and a PLC via port 102/tcp (ISO-TSAP) insufficiently protects the transmitted password. This could allow an attacker that is able to intercept the network traffic to obtain valid PLC credentials.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-252-02 updated cvss 5.9

Siemens SIMATIC S7-300 and S7-400 CPUs (Update C)

  • Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) Siemens SIMATIC S7-400 CPU family (incl. SIPLUS variants) Siemens SIMATIC WinAC RTX (F) 2010 Siemens SINUMERIK 840D sl
    affected: vendor fix siemens.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 3.3 AV:A/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants)
  • Siemens SIMATIC S7-400 CPU family (incl. SIPLUS variants)
  • Siemens SIMATIC WinAC RTX (F) 2010
  • Siemens SINUMERIK 840D sl

Classification

Weakness
  • CWE-522 Insufficiently Protected Credentials

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.