CVE-2019-16920
CVE-2019-16920 is a security flaw in D-Link Multiple Routers, routers for homes and small offices. Attackers can run their own code on D-Link Multiple Routers from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 Mar 2022.[1]
D-Link Multiple Routers is in things households have: home and small-office routers, so the fix matters at home as much as at work.
Description
CISA calls it a command injection in D-Link Multiple Routers. In its words: “Multiple D-Link routers contain a command injection vulnerability which can allow attackers to achieve full system compromise.”[1]
The CVE record adds: “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.”[2]
The underlying weakness is OS command injection (CWE-78), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it. CISA names the product as D-Link Multiple Routers.
Every device with D-Link Multiple Routers needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 25 Mar 2022, 910 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Apr 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at over 99%. That’s in the top 1% of the flaws it scores.[3]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
CISA’s required action: “The impacted product is end-of-life and should be disconnected if still in use.”[1]
- Update D-Link Multiple Routers now.Open the router’s app, or its admin page in a browser, and look for a firmware update. Then turn on automatic updates, so the next fix arrives on its own.
- If the maker has stopped updating it, replace it.Routers stop getting fixes after a few years, and attackers keep a list of the ones that did. If there’s no newer firmware, it won’t be fixed.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at over 99%.[3] |
See also
Other D-Link Multiple Routers flaws
- CVE-2018-6530: OS command injection ·
- CVE-2021-45382: remote code execution ·
Other D-Link flaws
- CVE-2025-29635, D-Link DIR-823X: command injection ·
- CVE-2022-37055, D-Link Routers: buffer overflow ·
- CVE-2022-40799, D-Link DNR-322L: download of code without integrity check ·
- CVE-2020-25079, D-Link DCS-2530L and DCS-2670L Devices: DCS-2530L and DCS-2670L command injection ·
- CVE-2020-25078, D-Link DCS-2530L and DCS-2670L Devices: unspecified ·
Other OS command injection flaws
- CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
- CVE-2026-106931, EG Secure Solutions SiteGuard Server Edition: OS command injection ·
- CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
- CVE-2026-49869, Kestra OSS: OSS OS command injection ·
- CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·
Added the same day
- CVE-2022-26318, WatchGuard Firebox and XTM Appliances: arbitrary code execution ·
- CVE-2022-26143, Mitel MiCollab, MiVoice Business Express: access control ·
- CVE-2022-21999, Microsoft Windows: print spooler privilege escalation ·
- CVE-2021-42237, Sitecore XP: remote command execution ·
- CVE-2021-22941, Citrix ShareFile: improper access control ·
Every D-Link flaw on CISA’s list · Everything added in March 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “D-Link Multiple Routers Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 25 Mar 2022.
- ^ National Institute of Standards and Technology. “CVE-2019-16920 Detail”. National Vulnerability Database, published 27 Sep 2019.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 1.000, percentile 100.0, 31 Oct 2026.
- CVE Program. “CVE-2019-16920”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.