Vulnerability record · CVE-2021-34204 · published 16 June 2021

CVE-2021-34204: Dlink dir-2640-us firmware insufficiently protected credentials vulnerability

Dlink · Dir 2640 Us Firmware

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.

6.8 CVSS 3.1 Medium EPSS 1.1% · top 35.3% CWE-522 · Insufficiently protected credentials

6.8CVSS 3.1 base score, v2 7.2

1.1%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

4References, 2 tagged exploit

9 Jul 2026Last modified by NVD

Description

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Dir 2640 Us Firmware Dlink

References

Link	Tags
https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34204	ExploitThird Party Advisory
https://www.dlink.com/en/security-bulletin/	Vendor Advisory
https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34204	ExploitThird Party Advisory
https://www.dlink.com/en/security-bulletin/	Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-34204), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.