CVE Catalog

CVE-2021-34203

HighCVSS 8.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Elevated risk
1.22%

65th percentile - higher than 65% of all known CVEs

Summary

D-Link DIR-2640-US router version 1.01B04 has an incorrect access control vulnerability. When setting up PPPoE, it starts the Quagga process for whole network monitoring using default credentials and port. An attacker can easily log in via Telnet, modify routing, monitor all device traffic, hijack DNS, and perform phishing attacks.

Risk Assessment

The risk includes full compromise of the router and the entire home or small office network. An attacker can take control of traffic, redirect users to malicious sites, and steal data.

Recommendation

Immediately update the router firmware to the latest version if a patch is available. Otherwise, consider replacing the device with a supported model and disable unused services like Telnet and Quagga.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS