CVE-2021-45382
CVE-2021-45382 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. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 4 Apr 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. D-Link has published a fix or advice.
Description
CISA calls it a remote code execution in D-Link Multiple Routers. In its words: “A remote code execution vulnerability exists in all series H/W revisions routers via the DDNS function in ncc2 binary file.”[1]
The CVE record adds: “A Remote Command Execution (RCE) vulnerability exists in all series H/W revisions D-link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L routers via the DDNS function in ncc2 binary file. Note: DIR-810L, DIR-820L, DIR-830L, DIR-826L, DIR-836L, all hardware revisions, have reached their End of Life ("EOL") /End of Service Life ("EOS") Life-Cycle and as such this issue will not be patched.”[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; D-Link’s advisory has them[3]. 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 4 Apr 2022, 46 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 25 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 98%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
D-Link has published a fix or advice.[3] 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 98%.[4] |
See also
Other D-Link Multiple Routers flaws
- CVE-2018-6530: OS command injection ·
- CVE-2019-16920: command injection ·
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-2022-22965, VMware Spring Framework: JDK 9+ remote code execution ·
- CVE-2022-22675, Apple macOS: out-of-bounds write ·
- CVE-2022-22674, Apple macOS: out-of-bounds read ·
Every D-Link flaw on CISA’s list · Everything added in April 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “D-Link Multiple Routers Remote Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 4 Apr 2022.
- ^ National Institute of Standards and Technology. “CVE-2021-45382 Detail”. National Vulnerability Database, published 17 Feb 2022.
- ^ D-Link. Advisories and fixes: supportannouncement.us.dlink.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.978, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2021-45382”. 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.