Cyber Resilience

CVE-2019-16920

RCE in Dlink Dir-655 Firmware ≤ 3.02b05

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCECommand Injection
Published
27 September 2019
Modified
07 November 2025
KEV Added
25 March 2022
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.99 100.0th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2019-16920 is a critical-severity OS Command Injection (CWE-78) vulnerability in Dlink Dir-655 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 0.0% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2019-16920 is an unauthenticated remote code execution vulnerability arising from OS command injection (CWE-78) in the PingTest device CGI of multiple D-Link router and access-point models, including DIR-655C, DIR-866L, DIR-652, DHP-1565, DIR-855L, DAP-1533, DIR-862L, DIR-615, DIR-835, and DIR-825. An attacker supplies crafted input that is passed directly to a system command without sanitization, resulting in arbitrary command execution on the affected device.

Because the flaw is reachable over the network without authentication or user interaction, any remote attacker who can reach the web interface can trigger the injection. Successful exploitation yields full system compromise, allowing the attacker to execute arbitrary commands with the privileges of the web server process.

Public references such as FortiGuard FG-VD-19-117, CERT VU#766427, and Seebug entries document the affected firmware versions and confirm the command-injection vector, but do not detail vendor-supplied patches or configuration work-arounds within the provided source material.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Unauthenticated remote code execution occurs in D-Link products such as DIR-655C, DIR-866L, DIR-652, and DHP-1565. The issue occurs when the attacker sends an arbitrary input to a "PingTest" device common gateway interface that could lead to common injection. An attacker…

more

who successfully triggers the command injection could achieve full system compromise. Later, it was independently found that these are also affected: DIR-855L, DAP-1533, DIR-862L, DIR-615, DIR-835, and DIR-825.

CWE(s)
KEV Date Added
25 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2019-17621Same vendor: Dlinkboth on KEV
CVE-2016-11021Same vendor: Dlinkboth on KEV
CVE-2019-20500Same vendor: Dlinkboth on KEV
CVE-2018-6530Same vendor: Dlinkboth on KEV
CVE-2022-26258Same vendor: Dlinkboth on KEV
CVE-2020-9377Same vendor: Dlinkboth on KEV
CVE-2019-16057Same vendor: Dlinkboth on KEV
CVE-2021-45382Same vendor: Dlinkboth on KEV
CVE-2023-25280Same vendor: Dlinkboth on KEV
CVE-2020-25506Same vendor: Dlinkboth on KEV

Affected Assets

dlink
dir-655 firmware
≤ 3.02b05
dlink
dir-866l firmware
≤ 1.03b04
dlink
dir-652 firmware
all versions
dlink
dhp-1565 firmware
≤ 1.01
dlink
dir-855l firmware
all versions
dlink
dap-1533 firmware
all versions
dlink
dir-862l firmware
all versions
dlink
dir-615 firmware
all versions
dlink
dir-835 firmware
all versions
dlink
dir-825 firmware
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References