Detect 403 forbidden endpoint bypass behind Nginx/Apache proxy & load balancers, based on X-Forwarded-For header.
The X-Forwarded-For (XFF) HTTP header field is a common method for identifying the originating IP address of a client connecting to a web server through an HTTP proxy or load balancer.
In cases where the recording mechanisms of web servers that can log HTTP headers fail to process the X-Forwarded-For header sent by the user, buffer overflow, command execution with web server rights, corruption of the file or format by entering corrupted data into the log files, etc. may be affected by security problems.
Sanitize all parameters received as input from the user.