CVE intelligence and bounded remediation

CVE-2020-5686 — Nec Univerge Sv9500 Firmware security vulnerability

High CVSS 7.5

Incorrect implementation of authentication algorithm issue in UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker to access the remote system maintenance feature and obtain the information by sending a specially crafted request to a specific URL.

Severity
High
CVSS
7.5 (3.1)
Published
2021-01-13
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-287

Affected products

  • nec / univerge_sv9500_firmware
  • nec / univerge_sv8500_firmware

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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