VULNERABILITY INTELLIGENCE
CVE-2021-37186
CVSS score5.4 MEDIUM
EPSS probability0.36%
CISA KEVNot currently listed
Published2021-09-14
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Description
A vulnerability has been identified in LOGO! CMR2020 (All versions < V2.2), LOGO! CMR2040 (All versions < V2.2), SIMATIC RTU3010C (All versions < V4.0.9), SIMATIC RTU3030C (All versions < V4.0.9), SIMATIC RTU3031C (All versions < V4.0.9), SIMATIC RTU3041C (All versions < V4.0.9). The underlying TCP/IP stack does not properly calculate the random numbers used as ISN (Initial Sequence Numbers). An adjacent attacker with network access to the LAN interface could interfere with traffic, spoof the connection and gain access to sensitive information.
Weakness classification
- CWE-330: Use of Insufficiently Random Values
Primary references
- productcert@siemens.com — Patch, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Vendor Advisory