CVE-2019-16920

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.

CVSS: 9.8Criticalscored by CISA
Exploited in the wild: Yes, in CISA KEV since 25 Mar 2022CISA deadline for US federal agencies: 15 Apr 2022unvetted proof-of-concept code on github
EPSS: > 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
Fix: Not stated by the vendorno fixed release in the CVE record
Published: 27 Sept 2019analysed here 12 Nov 2026

Do first. The impacted product is end-of-life and should be disconnected if still in use. (CISA's required action for this KEV entry)

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-78 OS Command Injection
Can a WAF block it?: Partly. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Products named in our analysis

dlink:dir-655_firmware
dlink:dir-866l_firmware
dlink:dir-652_firmware
dlink:dhp-1565_firmware
dlink:dir-855l_firmware
dlink:dap-1533_firmware
dlink:dir-862l_firmware
dlink:dir-615_firmware
dlink:dir-835_firmware
dlink:dir-825_firmware

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. OS command injection puts shell syntax into the request. WAF rules catch common shell commands but miss encoded or unusual payloads.

Also consider: shlex/execve-style APIs

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Listed since 25 Mar 2022.
CISA due date: 15 Apr 2022, the remediation deadline for US federal agencies
CISA required action: The impacted product is end-of-life and should be disconnected if still in use.
Public exploit code: Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept · 1 Nuclei template
CISA SSVC: exploitation active, automatable yes, technical impact totalAssessed by CISA 4 Feb 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

Nuclei

D-Link Routers - Remote Code Executiondetection template, critical

GitHub proofs of concept

eniac888/CVE-2019-16920-MassPwn3r1 stars

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

27 Sept 2019Published
16 Oct 2019First proof-of-concept repository on GitHub (unvetted)18 days later
25 Mar 2022Added to CISA KEV (exploited in the wild)891 days (about 2 years) later
15 Apr 2022CISA remediation due date (US federal agencies)21 days later
4 Feb 2025CISA SSVC assessment: exploitation active1,027 days (about 3 years) later
21 Oct 2025CVE record last updated259 days (about 9 months) later
12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	HighTotal data disclosure possible.	Total data disclosure possible.
Integrity	HighComplete modification possible.	Complete modification possible.
Availability	HighFull outage possible.	Full outage possible.

Common questions

Is CVE-2019-16920 being exploited?

Yes. CVE-2019-16920 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2019-16920?

CVE-2019-16920 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2019-16920?

Not known from our data. No patch reference has been recorded for CVE-2019-16920, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.

What does CVE-2019-16920 affect?

CVE-2019-16920 affects dlink:dir-655_firmware, dlink:dir-866l_firmware, dlink:dir-652_firmware, dlink:dhp-1565_firmware, and 6 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

5 references in the CVE record, grouped by the tags the record gives them.

Advisories (1)

kb.cert.org /vuls/id/766427

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA KEV catalog: exploitation, date added, due date
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
Nuclei templates: detection templates
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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