CVE intelligence and bounded remediation

CVE-2023-3373 — Mitsubishielectric Gt21 Firmware security vulnerability

Critical CVSS 9.1

Predictable Exact Value from Previous Values vulnerability in Mitsubishi Electric Corporation GOT2000 Series GT21 model versions 01.49.000 and prior and GOT SIMPLE Series GS21 model versions 01.49.000 and prior allows a remote unauthenticated attacker to hijack data connections (session hijacking) or prevent legitimate users from establishing data connections (to cause DoS condition) by guessing the listening port of the data connection on FTP server and connecting to it.

Severity
Critical
CVSS
9.1 (3.1)
Published
2023-08-04
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-342, CWE-330

Affected products

  • mitsubishielectric / gt21_firmware
  • mitsubishielectric / gs21_firmware

Matched remediation archetype

Cryptography, certificate, signature, and channel validation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory affected algorithms, key uses, trust stores, certificate validation settings, random sources, and plaintext channels across clients and services.
  • Determine which secrets, identities, signatures, or data protections depend on the affected primitive or validation path.
  • Check debug, compatibility, fallback, and hostname or audience override settings in build and runtime configuration.

Remediate safely

  • Use a maintained platform cryptographic API with approved algorithms, modes, parameters, randomness, and full peer identity validation.
  • Remove insecure fallback and validation bypasses; separate keys by purpose and load them from managed secret storage.
  • Plan rotation or reissuance for affected keys, certificates, tokens, hashes, or ciphertext and document compatibility sequencing.

Authoritative sources

Complete CVE record and remediation plan

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