Update 512-pentesting-rexec.md

Author: carlospolop

src/network-services-pentesting/512-pentesting-rexec.md

@@ -46,6 +46,8 @@ If `-p` is omitted the client will prompt interactively for the password (visibl
 ---
 ## Enumeration & Brute-forcing
 
+### [**Brute-force**](../generic-hacking/brute-force.md#rexec)
+
 ### Nmap
 
 ```bash