Cyber Resilience

CVE-2020-28397

Medium

Published: 10 August 2021

Published
10 August 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0018 39.9th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2020-28397 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Siemens Siplus Cpu 1511-1 Pn Firmware. Its CVSS base score is 5.3 (Medium).

Operationally, ranked at the 39.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

siemens
cpu 1504d tf firmware
≤ 2.9.2
siemens
cpu 1507d tf firmware
≤ 2.9.2
siemens
cpu 1515sp pc2 tf firmware
≤ 21.9
siemens
simatic s7 plcsim advanced firmware
2.0 — 4.0
siemens
simatic s7-1500 software controller
2.5 — 21.9
siemens
tim 1531 irc firmware
2.1
siemens
cpu 1211c firmware
4.4
siemens
cpu 1212c firmware
4.4
siemens
cpu 1212fc firmware
4.4
siemens
cpu 1214fc firmware
4.4
+46 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-863

Periodic review and update of procedures reduces incorrect authorization implementations over time.

addresses: CWE-863

Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.

addresses: CWE-863

Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.

addresses: CWE-863

The authorization process and usage restrictions help prevent incorrect authorization for remote access types.

addresses: CWE-863

Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.

addresses: CWE-863

Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.

addresses: CWE-863

Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.

addresses: CWE-863

Ensures authorization decisions for external system use are correctly implemented and enforced.

References