CVE-2021-34203
mediumpriority · track · 32OT risk · elevatedEPSS 0.012 · 68 %ileEURUUSEPSS · scored 2026-10-28
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 4.8–9.4
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (8)
External citations — patches, advisories, analysis.
- http://d-link.comcnnvd
- http://dir-2640-us.comcnnvd
- https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203cnnvd
- https://www.dlink.com/en/security-bulletin/cnnvd
- https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203enisa_euvd
- https://www.dlink.com/en/security-bulletin/enisa_euvd
- https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203ExploitThird Party Advisorynvd
- https://www.dlink.com/en/security-bulletin/Vendor Advisorynvd
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