CVE-2020-21016: D-Link DIR-846 devices with firmware 100A35 allow remote attackers to execute arbitrary code as root via HNAP1

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CRITICAL 9.8REMOTEMITIGATE

CVE-2020-21016 is a critical-severity flaw (CVSS 9.8) affecting dir-846 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

D-Link DIR-846 devices with firmware 100A35 allow remote attackers to execute arbitrary code as root via HNAP1/control/SetGuestWLanSettings.php.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-94
Published	2022-10-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: dlink

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-10-31 13:15 UTCPublished CVE record published
2026-06-17 03:03 UTCUpdated Record last modified

dlink dir-846 firmware MITIGATE

Affected: 100a35

Fixed in: no fixed release known

Safe to downgrade to: a release before 100a35

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-21016?

dir-846 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-21016 being exploited?

CVE-2020-21016 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-21016 affect?

CVE-2020-21016 affects dir-846 firmware. Severity is critical (CVSS 9.8). D-Link DIR-846 devices with firmware 100A35 allow remote attackers to execute arbitrary code as root via HNAP1/control/SetGuestWLanSettings.php.

How urgent is CVE-2020-21016?

Priority 66/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities · D-Link vulnerabilities

Related CVEs

CVE-2023-6580 HIGH 8.8 MITIGATE A vulnerability, which was classified as critical, was found in D-Link DIR-846 FW100A53DBR
CVE-2023-43284 HIGH 8.8 MITIGATE D-Link Wireless MU-MIMO Gigabit AC1200 Router DIR-846 100A53DBR-Retail devices allow an authenticated remote a
CVE-2022-46642 CRITICAL 9.9 MITIGATE D-Link DIR-846 A1_FW100A43 was discovered to contain a command injection vulnerability via the auto_upgrade_ho
CVE-2022-46641 CRITICAL 9.9 MITIGATE D-Link DIR-846 A1_FW100A43 was discovered to contain a command injection vulnerability via the lan(0)_dhcps_st
CVE-2022-46552 HIGH 8.8 MITIGATE D-Link DIR-846 Firmware FW100A53DBR was discovered to contain a remote command execution (RCE) vulnerability v

References

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