CVE intelligence and bounded remediation

CVE-2020-28391 — A vulnerability has been identified in SCALANCE X-200 switch family (incl

Medium CVSS 5.9

A vulnerability has been identified in SCALANCE X-200 switch family (incl. SIPLUS NET variants) (All versions < V5.2.5), SCALANCE X-200IRT switch family (incl. SIPLUS NET variants) (All versions < V5.5.0), SCALANCE X-200RNA switch family (All versions < V3.2.7). Devices create a new unique key upon factory reset, except when used with C-PLUG. When used with C-PLUG the devices use the hardcoded private RSA-key shipped with the firmware-image. An attacker could leverage this situation to a man-in-the-middle situation and decrypt previously captured traffic.

Severity
Medium
CVSS
5.9 (3.1)
Published
2021-01-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-321, CWE-798

Affected products

  • siemens / scalance_x200-4pirt_firmware
  • siemens / scalance_x201-3pirt_firmware
  • siemens / scalance_x202-2irt_firmware
  • siemens / scalance_x202-2pirt_firmware
  • siemens / scalance_x202-2pirt_siplus_net_firmware
  • siemens / scalance_x204irt_firmware

Showing 6 representative product identities from 66 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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