CVE-2021-34203

high

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.

References

https://www.dlink.com/en/security-bulletin/

https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203

http://dir-2640-us.com

http://d-link.com

Details

Source: Mitre, NVD

Published: 2021-06-16

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 4.8

Vector: CVSS2#AV:A/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 8.1

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

Severity: High

EPSS

EPSS: 0.00069