---
id: CVE-2021-34204
title: D-Link DIR-2640-US 1.01B04 is affected by Insufficiently Protected Credentials
summary: >-
  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 dev…
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-522
vendor: dlink
product: dir-2640-us_firmware
affected:
  - dir-2640-us_firmware = 1.01b04
published: '2021-06-16'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-34204'
references:
  - url: 'https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34204'
    label: cve@mitre.org
  - url: 'https://www.dlink.com/en/security-bulletin/'
    label: cve@mitre.org
  - url: 'http://d-link.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://dir-2640-us.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34204'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.dlink.com/en/security-bulletin/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01115
epssPercentile: 0.64625
ingestedAt: '2026-07-06T01:08:16.780Z'
---

## Overview

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.

## Affected

- `dir-2640-us_firmware = 1.01b04`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.