CVE intelligence and bounded remediation

CVE-2020-3234 — Cisco Ios security vulnerability

High CVSS 8.8

A vulnerability in the virtual console authentication of Cisco IOS Software for Cisco 809 and 829 Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an authenticated but low-privileged, local attacker to log in to the Virtual Device Server (VDS) of an affected device by using a set of default credentials. The vulnerability is due to the presence of weak, hard-coded credentials. An attacker could exploit this vulnerability by authenticating to the targeted device and then connecting to VDS through the device’s virtual console by using the static credentials. A successful exploit could allow the attacker to access the Linux shell of VDS as the root user.

Severity
High
CVSS
8.8 (3.1)
Published
2020-06-03
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-798

Affected products

  • cisco / ios / 12.2(60)ez16
  • cisco / ios / 15.0(2)sg11a
  • cisco / ios / 15.3(3)jaa1
  • cisco / ios / 15.3(3)jpj
  • cisco / ios / 15.4(1)cg
  • cisco / ios / 15.4(2)cg

Showing 6 representative product identities from 87 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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