What’s Vulnerable › Vulnerabilities

CVE-2021-25676

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-15 · updated 2026-06-17
• Weakness: CWE-307

Description

A vulnerability has been identified in RUGGEDCOM RM1224 (V6.3), SCALANCE M-800 (V6.3), SCALANCE S615 (V6.3), SCALANCE SC-600 (All Versions >= V2.1 and < V2.1.3). Multiple failed SSH authentication attempts could trigger a temporary Denial-of-Service under certain conditions. When triggered, the device will reboot automatically.

Affected products

• Siemens Ruggedcom Rm1224 Firmware: 6.3
• Siemens Scalance M-800 Firmware: 6.3
• Siemens Scalance S615 Firmware: 6.3
• Siemens AG SCALANCE SC-600: from 2.1 before 2.1.3 — fixed in 2.1.3

How to fix

Upgrade to a fixed version: Siemens AG SCALANCE SC-600 2.1.3. Check the vendor advisory for mitigations.

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-296266.pdf
• https://us-cert.cisa.gov/ics/advisories/icsa-21-068-02
• https://cert-portal.siemens.com/productcert/pdf/ssa-296266.pdf
• https://us-cert.cisa.gov/ics/advisories/icsa-21-068-02

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