CVE-2021-34204 Hardcoded credentials in n/a

Medium 6.8 Published 16 Jun 2021 Updated 9 Jul 2026

An attacker with serial access can obtain root privileges on D-Link DIR-2640 routers due to hardcoded, plain-text system credentials.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-34204?

CVE-2021-34204 is a medium-severity vulnerability in n/a, published on 16 Jun 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

D-Link DIR-2640-US 1.01B04 is affected by Insufficiently Protected Credentials. D-Link AC2600(DIR-2640) stores the device system account password in plain text. It does not use linux user management. In addition, the passwords of all devices are the same, and they cannot be modified by normal users. An attacker can easily log in to the target router through the serial port and obtain root privileges.

Weakness: CWE-522

Which versions are affected by CVE-2021-34204?

It affects 1 product.

Products include Dlink Dir-2640-Us Firmware.

How do I fix CVE-2021-34204?

No fix has been published for CVE-2021-34204 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-34204 being exploited?

There is no known exploitation of CVE-2021-34204 in the wild and no public exploit code.

Sources

Also known as GHSA-m45q-r6x2-5q77.