Vulnerability related to URL redirection via rk.php and redirect.php
Bitrix CMS is a popular content management system used for creating websites and online stores. However, like any other web application, Bitrix CMS can have vulnerabilities that can be exploited by attackers to launch attacks on a website. One such vulnerability is related to redirects to rk.php and redirect.php.
How do redirects to rk.php and redirect.php work in Bitrix CMS?
In Bitrix CMS, rk.php and redirect.php are files used to redirect users to other pages. For example, if a user enters an incorrect page address, they can be redirected to an error page or another page on the website. These files are used in combination with URL parameters to redirect the user to the intended page.
What is the vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS?
The vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS is that attackers can use these files to redirect users to other websites or pages that may contain malicious code. For example, an attacker could create a fake login page and use rk.php or redirect.php to redirect the user to this page. The attacker could then ask the user to enter their credentials, which would be used to gain unauthorized access to their account.
How to avoid vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS?
To avoid the vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS, it is important to use only reliable and verified sources for redirection. Never click on links that you receive from unknown sources or that you did not expect to receive. If you are unsure about the authenticity of a link, it is better to use a search engine to find the desired website.
If you are developing a website on Bitrix CMS, you need to carefully check all links for redirects, using only reliable and verified sources. You should also use input validation and filter out incorrect URL addresses that can be used by attackers to redirect users to other websites.
One of the methods of protecting against the vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS is to add a rule to the Nginx configuration file. This rule prohibits access to the rk.php and redirect.php files located in the /bitrix/ directory on your server.
Adding the following rule to the Nginx configuration file will help protect your site from the vulnerability related to redirects to rk.php and redirect.php:
location ~* ^/bitrix/(rk|redirect)\.php$ {
deny all;
}
This rule prohibits access to the rk.php and redirect.php files located in the /bitrix/ directory on your server. Thus, attackers will not be able to use these files to redirect users to other websites or pages.
This configuration should be added to the Nginx configuration file, which is usually located in the /etc/nginx/ directory and named nginx.conf. In this file, you need to find the server block and add the rule inside the location block:
server {
...
location / {
...
}
location ~* ^/bitrix/(rk|redirect)\.php$ {
deny all;
}
...
}
After adding the rule, you need to save the changes to the configuration file and restart the Nginx server for the changes to take effect:
sudo service nginx restart
or if you are using systemd
sudo systemctl restart nginx
Note that when using a different server, such as Apache, you need to use the corresponding configuration file.
In conclusion, the vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS is a serious threat to the security of the website. To avoid this vulnerability, it is important to use only reliable and verified sources for redirection, use input validation and filter out incorrect URL addresses, and use additional security methods. Adding a rule to the Nginx configuration file will also help protect your site from the vulnerability related to redirects to rk.php and redirect.php in Bitrix CMS.
