Netgear D6400 Vulnerabilities & CVEs

Q: Is my Netgear D6400 affected by these vulnerabilities?

Only if you’re running a firmware version in the affected range listed above and haven’t updated. Check your router's admin panel for its current firmware version and compare it against the ranges below.

Q: How do I update my Netgear D6400's firmware?

Log into the router's web admin panel (usually at its local IP address) and look for a Firmware Update or System Update section, or use the vendor's mobile app if it has one.

Q: Does ProbeShield fix these vulnerabilities for me?

No — ProbeShield scans your network and tells you what it finds (open ports, default credentials, outdated firmware signals) so you know what to fix, and how. It never changes your devices’ settings.

Known CVEs

CVE-2021-38516CRITICAL (10)

Certain NETGEAR devices are affected by lack of access control at the function level. This affects D6220 before 1.0.0.48, D6400 before 1.0.0.82, D7000v2 before 1.0.0.52, D7800 before 1.0.1.44, D8500 before 1.0.3.43, D...

Affected: versions < 1.0.0.82Fixed in: 1.0.0.82

CVE-2019-20730CRITICAL (9.8)

Certain NETGEAR devices are affected by SQL injection. This affects D3600 before 1.0.0.68, D6000 before 1.0.0.68, D6200 before 1.1.00.28, D6220 before 1.0.0.40, D6400 before 1.0.0.74, D7000 before 1.0.1.60, D7000v2 be...

Affected: versions < 1.0.0.74Fixed in: 1.0.0.74

CVE-2018-21134CRITICAL (9.8)

Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects R6700 before 1.0.1.48, R7900 before 1.0.2.16, R6900 before 1.0.1.48, R7000P before 1.3.1.44, R6900P be...

Affected: versions < 1.0.0.82Fixed in: 1.0.0.82

CVE-2018-21162CRITICAL (9.8)

Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects D6400 before 1.0.0.78, EX6200 before 1.0.3.86, EX7000 before 1.0.0.64, R6250 before 1.0.4.8, R6300v2 before 1.0.4....

Affected: versions < 1.0.0.78Fixed in: 1.0.0.78

CVE-2021-45527CRITICAL (9.6)

Certain NETGEAR devices are affected by a buffer overflow by an authenticated user. This affects D6220 before 1.0.0.68, D6400 before 1.0.0.102, D7000v2 before 1.0.0.66, D8500 before 1.0.3.58, DC112A before 1.0.0.54, E...

Affected: versions < 1.0.0.102Fixed in: 1.0.0.102

CVE-2021-45610CRITICAL (9.6)

Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D6220 before 1.0.0.66, D6400 before 1.0.0.100, D7000v2 before 1.0.0.66, D8500 before 1.0.3.58, DC112A before 1.0.0...

Affected: versions < 1.0.0.100Fixed in: 1.0.0.100

CVE-2021-45638CRITICAL (9.6)

Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects D6220 before 1.0.0.68, D6400 before 1.0.0.102, D7000v2 before 1.0.0.74, D8500 before 1.0.3.60, DC112A ...

Affected: versions < 1.0.0.102Fixed in: 1.0.0.102

CVE-2020-35800CRITICAL (9.4)

Certain NETGEAR devices are affected by incorrect configuration of security settings. This affects AC2100 before 1.2.0.72, AC2400 before 1.2.0.72, AC2600 before 1.2.0.72, CBK40 before 2.5.0.10, CBR40 before 2.5.0.10, ...

Affected: versions < 1.0.0.94Fixed in: 1.0.0.94

CVE-2016-6277HIGH (8.8)CISA KEV

NETGEAR R6250 before 1.0.4.6.Beta, R6400 before 1.0.1.18.Beta, R6700 before 1.0.1.14.Beta, R6900, R7000 before 1.0.7.6.Beta, R7100LG before 1.0.0.28.Beta, R7300DST before 1.0.0.46.Beta, R7900 before 1.0.1.8.Beta, R800...

Affected: versions <= 1.0.0.56Fixed in: later than 1.0.0.56

CVE-2020-11770HIGH (8.8)

Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D6220 before 1.0.0.52, D6400 before 1.0.0.86, D7000v2 before 1.0.0.53, D8500 before 1.0.3.44, R6220 before 1.1.0.80, R62...

Affected: versions < 1.0.0.86Fixed in: 1.0.0.86

Commonly exposed ports

Port 23 (Telnet) — Sends admin credentials unencrypted — a common target on older router firmware.
Port 80 (HTTP admin panel) — The web admin UI; dangerous if remote/WAN administration is left enabled.
Port 7547 (TR-069 (CWMP)) — ISP remote-management protocol — has been the entry point for several router botnets.
Port 1900 (UPnP/SSDP) — Lets apps on your LAN open firewall holes automatically, sometimes without your knowledge.

Default credentials

From ProbeShield's own tested default-credential list (see probeshield.com/default-passwords/): "netgear" / "password" or "admin" / "netgear1" or "admin" / "password123" over HTTP.

Hardening checklist

Disable remote (WAN-side) administration unless you specifically need it.
Turn off UPnP unless a specific app you trust requires it.
Turn off WPS — it can let an attacker bypass your Wi-Fi password.
Change the default admin username and password to something unique.
Check for a firmware update in the router’s admin panel and apply it.
Disable Telnet/SSH management access if you don’t actively use it.

Frequently asked questions

Is my Netgear D6400 affected by these vulnerabilities? Only if you’re running a firmware version in the affected range listed above and haven’t updated. Check your router's admin panel for its current firmware version and compare it against the ranges below.

How do I update my Netgear D6400's firmware? Log into the router's web admin panel (usually at its local IP address) and look for a Firmware Update or System Update section, or use the vendor's mobile app if it has one.

Does ProbeShield fix these vulnerabilities for me? No — ProbeShield scans your network and tells you what it finds (open ports, default credentials, outdated firmware signals) so you know what to fix, and how. It never changes your devices’ settings.

Sources: National Vulnerability Database (NVD), CISA Known Exploited Vulnerabilities Catalog. This page lists which firmware versions are affected — it doesn't claim your specific unit is vulnerable. Check your device's current firmware version in its admin panel and compare it against the ranges above.