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.
CVE-2021-37186
Score 5.4 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.4; sources differ by 0.0.
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(medium)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity54% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 28.1%
- KEV
- Not listed
Published
September 14, 2021
Last Modified
November 21, 2024
References (2)
- productcert@siemenshttps://cert-portal.siemens.com/productcert/pdf/ssa-316383.pdf
- af854a3a-2127-422b-91ae-364da2661108https://cert-portal.siemens.com/productcert/pdf/ssa-316383.pdf
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 44× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 02:03 UTCEG score recompute
- 2026-07-22 22:49 UTCEG score recompute
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Related CVEs(same CWE)
Same CWE
10 shownCWE-330
- CVE-2020-1472EG 10.0 KEVEPSS 100%CRITICAL
- CVE-2019-0007NVD 9.3EG 10.0CRITICAL
- CVE-2019-2317EG 9.8CRITICAL
- CVE-2019-16674EG 9.8CRITICAL
- CVE-2014-6311EG 9.8CRITICAL
- CVE-2019-2294EG 9.8CRITICAL
- CVE-2019-15130EG 9.8CRITICAL
- CVE-2019-7667EG 9.8EPSS 90%CRITICAL
- CVE-2019-9863EG 9.8CRITICAL
- CVE-2019-5420EG 9.8EPSS 100%CRITICAL
Frequently asked(5)
What is CVE-2021-37186?
When was CVE-2021-37186 disclosed?
Is CVE-2021-37186 actively exploited?
What is the CVSS score of CVE-2021-37186?
How do I remediate CVE-2021-37186?
Dependency Blast Radius
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