CVE-2021-34203 - CVE House
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Status published High CVE-2021-34203

D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router...

Vulnerability Description

D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router ac2600 (dir-2640-us), when setting PPPoE, will start quagga process in the way of whole network monitoring, and this function uses the original default password and port. An attacker can easily use telnet to log in, modify routing information, monitor the traffic of all devices under the router, hijack DNS and phishing attacks. In addition, this interface is likely to be questioned by customers as a backdoor, because the interface should not be exposed.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

dir-2640-us firmware
Vulnerable Versions:
1.01b04

Timeline

Official Publish: June 16th, 2021
Last Modified: July 9th, 2026
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.