CVE intelligence and bounded remediation

CVE-2021-31505 — This vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278

High CVSS 7.2

This vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SSH service. The device can be booted into a special operation mode where hard-coded credentials are accepted for SSH authentication. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. Was ZDI-CAN-12890.

Severity
High
CVSS
7.2 (2.0)
Published
2021-06-29
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-798

Affected products

  • arlo / q_plus_firmware / 1.9.0.3_278

Matched remediation archetype

Authentication bypass and missing authentication

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

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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