^{CVE-2020-29321:}D-Link DIR-868L router contains hardcoded credentials in its telnet service, allowing unauthorized access to the firmware.

Overview

This vulnerability affects the D-Link DIR-868L router running firmware version 3.01. The issue stems from hardcoded credentials embedded in the telnet service of the router. An attacker with the ability to decompile the firmware can extract these credentials, which can then be used to authenticate to the telnet service. This provides unauthorized access to the router's internal systems and sensitive data. The vulnerability requires no authentication to exploit, making it particularly dangerous as it can be leveraged remotely by attackers to gain privileged access to the affected devices. This type of vulnerability is commonly exploited in targeted attacks against network infrastructure.

Remediation

1. Update firmware: Check for and install any security updates or patches released by D-Link for the DIR-868L router.
2. Disable telnet: If possible, disable the telnet service on the router as it is an insecure protocol.
3. Network segmentation: Place the router in a segregated network with limited access from untrusted networks.
4. Replace the device: If D-Link has not provided a patch, consider replacing the router with a more secure model.
5. Monitor for suspicious activity: Implement network monitoring to detect unauthorized access attempts.
6. Change default credentials: Change any configurable passwords on the device, though this will not address the hardcoded credentials issue.
7. Implement a firewall: Configure a firewall to restrict access to the router's management interfaces from untrusted networks.

References

1. https://cybersecurityworks.com/zerodays/cve-2020-29321-telnet-hardcoded-credentials.html - Contains detailed information about the vulnerability and exploitation techniques.
2. CWE-798: https://cwe.mitre.org/data/definitions/798.html - Information about the Use of Hard-coded Credentials vulnerability type.
3. CWE-522: https://cwe.mitre.org/data/definitions/522.html - Information about Insufficiently Protected Credentials vulnerability type.
4. D-Link security advisories: Check D-Link's official security advisory page for potential updates or patches.