CVE intelligence and bounded remediation

CVE-2019-17621 — D-Link DIR-859 Router Command Execution Vulnerability

Critical CVSS 9.8 CISA KEV

The UPnP endpoint URL /gena.cgi in the D-Link DIR-859 Wi-Fi router 1.05 and 1.06B01 Beta01 allows an Unauthenticated remote attacker to execute system commands as root, by sending a specially crafted HTTP SUBSCRIBE request to the UPnP service when connecting to the local network.

Severity
Critical
CVSS
9.8 (3.1)
Published
2019-12-30
CISA KEV
Known exploited
Ecosystem
operating-system
Weaknesses
CWE-78

Affected products

  • dlink / dir-859_firmware
  • dlink / dir-859_firmware / 1.06b01
  • dlink / dir-822_firmware
  • dlink / dir-823_firmware
  • dlink / dir-823_firmware / 1.00b06
  • dlink / dir-865l_firmware

Showing 6 representative product identities from 21 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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