An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-27342
• https://blog.whtaguy.com/2021/05/d-link-router-cve-2021-27342.html
• https://github.com/guywhataguy/D-Link-CVE-2021-27342-exploit/blob/main/dlink-telnet-exploit-CVE-2021-27342.py
• https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10225