Auth bypass in Siemens CPU 1211c

CVE-2020-28397

A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions < V21.9), SIMATIC S7 PLCSIM Advanced (All versions > V2 < V4), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (Version V4.4), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions > V2.5 < V2.9.2), SIMATIC S7-1500 Software Controller (All versions > V2.5 < V21.9), TIM 1531 IRC (incl. SIPLUS NET variants) (Version V2.1). Due to an incorrect authorization check in the affected component, an attacker could extract information about access protected PLC program variables over port 102/tcp from an affected device when reading multiple attributes at once.

Vulnerability class: Broken Access Control

EPSS: 0.008 (52.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-28397?
CVE-2020-28397 is a medium-severity vulnerability in Siemens CPU 1211c, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2021-08-10.
How severe is CVE-2020-28397?
Medium severity. CVSS v3 base score is 5.3 out of 10.