6번
페이지에서 소스코드를 제공하기 때문에 한번 해석해보자.
<?php
include "../../config.php";
if($_GET['view_source']) view_source();
if(!$_COOKIE['user']){
$val_id="guest";
$val_pw="123qwe";
for($i=0;$i<20;$i++){
$val_id=base64_encode($val_id);
$val_pw=base64_encode($val_pw);
}
$val_id=str_replace("1","!",$val_id);
$val_id=str_replace("2","@",$val_id);
$val_id=str_replace("3","$",$val_id);
$val_id=str_replace("4","^",$val_id);
$val_id=str_replace("5","&",$val_id);
$val_id=str_replace("6","*",$val_id);
$val_id=str_replace("7","(",$val_id);
$val_id=str_replace("8",")",$val_id);
$val_pw=str_replace("1","!",$val_pw);
$val_pw=str_replace("2","@",$val_pw);
$val_pw=str_replace("3","$",$val_pw);
$val_pw=str_replace("4","^",$val_pw);
$val_pw=str_replace("5","&",$val_pw);
$val_pw=str_replace("6","*",$val_pw);
$val_pw=str_replace("7","(",$val_pw);
$val_pw=str_replace("8",")",$val_pw);
Setcookie("user",$val_id,time()+86400,"/challenge/web-06/");
Setcookie("password",$val_pw,time()+86400,"/challenge/web-06/");
echo("<meta http-equiv=refresh content=0>");
exit;
}
?>
<html>
<head>
<title>Challenge 6</title>
<style type="text/css">
body { background:black; color:white; font-size:10pt; }
</style>
</head>
<body>
<?php
$decode_id=$_COOKIE['user'];
$decode_pw=$_COOKIE['password'];
$decode_id=str_replace("!","1",$decode_id);
$decode_id=str_replace("@","2",$decode_id);
$decode_id=str_replace("$","3",$decode_id);
$decode_id=str_replace("^","4",$decode_id);
$decode_id=str_replace("&","5",$decode_id);
$decode_id=str_replace("*","6",$decode_id);
$decode_id=str_replace("(","7",$decode_id);
$decode_id=str_replace(")","8",$decode_id);
$decode_pw=str_replace("!","1",$decode_pw);
$decode_pw=str_replace("@","2",$decode_pw);
$decode_pw=str_replace("$","3",$decode_pw);
$decode_pw=str_replace("^","4",$decode_pw);
$decode_pw=str_replace("&","5",$decode_pw);
$decode_pw=str_replace("*","6",$decode_pw);
$decode_pw=str_replace("(","7",$decode_pw);
$decode_pw=str_replace(")","8",$decode_pw);
for($i=0;$i<20;$i++){
$decode_id=base64_decode($decode_id);
$decode_pw=base64_decode($decode_pw);
}
echo("<hr><a href=./?view_source=1 style=color:yellow;>view-source</a><br><br>");
echo("ID : $decode_id<br>PW : $decode_pw<hr>");
if($decode_id=="admin" && $decode_pw=="nimda"){
solve(6);
}
?>
</body>
</html>1,2,3,4,5,6,7,8,9,0 을 shift키를 눌렀을 때 변하는 특수문자로 변환하고 base64 인코딩을 20번한다. 해석할 때는 이를 반대로 수행해주고, 그 결과가 admin과 nimda가 나오면 된다. 위코드를 그대로 사용하여 admin과 nimda를 인코딩 해주면 된다.
id: Vm0wd@QyUXlVWGxWV0d^V!YwZDRWMVl$WkRSV0!WbDNXa!JTVjAxV@JETlhhMUpUVmpBeFYySkVUbGhoTVVwVVZtcEJlRll&U@tWVWJHaG9UVlZ$VlZadGNFSmxSbGw!VTJ0V!ZXSkhhRzlVVmxaM!ZsWmFjVkZ0UmxSTmJFcEpWbTEwYTFkSFNrZGpSVGxhVmpOU!IxcFZXbUZrUjA!R!UyMTRVMkpIZHpGV!ZFb$dWakZhV0ZOcmFHaFNlbXhXVm!wT!QwMHhjRlpYYlVaclVqQTFSMWRyV@&kV0!ERkZVbFJHVjFaRmIzZFdha!poVjBaT@NtRkhhRk&sYlhoWFZtMXdUMVF$TUhoalJscFlZbGhTV0ZSV@FFTlNiRnBZWlVaT!ZXSlZXVEpWYkZKRFZqQXhkVlZ!V@xaaGExcFlXa!ZhVDJOc@NFZGhSMnhUVFcxb@IxWXhaREJaVmxsM!RVaG9hbEpzY0ZsWmJGWmhZMnhXY!ZGVVJsTk&WMUo!VmpKNFQxWlhTbFpYVkVwV!lrWktTRlpxUm!GU@JVbDZXa!prYUdFeGNHOVdha0poVkRKT@RGSnJhR@hTYXpWeldXeG9iMWRHV@&STldHUlZUVlpHTTFSVmFHOWhiRXB*WTBac!dtSkdXbWhaTVZwaFpFZFNTRkpyTlZOaVJtOTNWMnhXWVZReFdsaFRiRnBZVmtWd!YxbHJXa$RUUmxweFVtMUdVMkpWYkRaWGExcHJZVWRGZUdOSE9WZGhhMHBvVmtSS!QyUkdTbkpoUjJoVFlYcFdlbGRYZUc&aU!XUkhWMjVTVGxOSGFGQlZiVEUwVmpGU!ZtRkhPVmhTTUhCNVZHeGFjMWR0U@tkWGJXaGFUVzVvV0ZreFdrZFdWa$B*VkdzMVYySkdhM@hXYTFwaFZURlZlRmR!U@s!WFJYQnhWVzB^YjFZeFVsaE9WazVPVFZad@VGVXlkREJXTVZweVkwWndXR0V^Y0ROV@FrWkxWakpPU!dKR!pGZFNWWEJ@Vm!0U!MxUXlUWGxVYTFwb!VqTkNWRmxZY0ZkWFZscFlZMFU!YVUxcmJEUldNalZUVkd^a!NGVnNXbFZXYkhCWVZHdGFWbVZIUmtoUFYyaHBVbGhDTmxkVVFtRmpNV!IwVTJ0a!dHSlhhR0ZVVnpWdlYwWnJlRmRyWkZkV@EzQjZWa@R*TVZZd0!WWmlla!pYWWxoQ!RGUnJXbEpsUm!SellVWlNhVkp!UW&oV!YzaHJWVEZzVjFWc!dsaGlWVnBQVkZaYWQyVkdWWGxrUkVKWFRWWndlVmt$V@&kWFIwVjRZMFJPV@!FeVVrZGFWM@hIWTIxS!IxcEhiRmhTVlhCS!ZtMTBVMU!^VlhoWFdHaFlZbXhhVjFsc!pHOVdSbXhaWTBaa@JHSkhVbGxhVldNMVlWVXhXRlZyYUZkTmFsWlVWa@Q0YTFOR!ZuTlhiRlpYWWtoQ!NWWkdVa@RWTVZwMFVtdG9VRll&YUhCVmJHaERUbXhrVlZGdFJtcE&WMUl$VlRKMGExZEhTbGhoUjBaVlZucFdkbFl$V@&OT@JFcHpXa@R$YVZORlNrbFdNblJyWXpGVmVWTnVTbFJpVlZwWVZGYzFiMWRHWkZkWGJFcHNVbTFTZWxsVldsTmhWa$AxVVd^d!YySllVbGhhUkVaYVpVZEtTVk&zYUdoTk!VcFZWbGN^TkdReVZrZFdiR!JvVW&wc@IxUldXbmRsYkZsNVkwVmtWMDFFUmpGWlZXaExWMnhhV0ZWclpHRldNMmhJV!RJeFMxSXhjRWhpUm!oVFZsaENTMVp0TVRCVk!VMTRWbGhvV0ZkSGFGbFpiWGhoVm!^c@NscEhPV$BTYkhCNFZrY$dOVll^V@&OalJXaFlWa!UxZGxsV!ZYaFhSbFp&WVVaa!RtRnNXbFZXYTJRMFdWWktjMVJ!VG!oU@JGcFlXV$hhUm!ReFduRlJiVVphVm0xU!NWWlhkRzloTVVwMFlVWlNWVlpXY0dGVVZscGhZekZ$UlZWdGNFNVdNVWwzVmxSS0!HRXhaRWhUYkdob!VqQmFWbFp0ZUhkTk!WcHlWMjFHYWxacmNEQmFSV!F$VmpKS@NsTnJhRmRTTTJob!ZrUktSMVl^VG&WVmJFSlhVbFJXV!ZaR!l*RmlNV!JIWWtaV!VsZEhhRlJVVm!SVFpXeHNWbGRzVG!oU!ZFWjZWVEkxYjFZeFdYcFZiR@hZVm!^d!lWcFZXbXRrVmtwelZtMXNWMUl*YURWV0!XUXdXVmRSZVZaclpGZGliRXB&Vld0V!MySXhiRmxqUldSc!ZteEtlbFp0TURWWFIwcEhZMFpvV@sxSGFFeFdNbmhoVjBaV@NscEhSbGROTW!oSlYxUkplRk!^U!hoalJXUmhVbXMxV0ZZd!ZrdE&iRnAwWTBWa!dsWXdWalJXYkdodlYwWmtTR0ZHV@xwaVdHaG9WbTE0YzJOc!pISmtSM0JUWWtad0&GWlhNVEJOUmxsNFYyNU9hbEpYYUZoV@FrNVRWRVpzVlZGWWFGTldhM0I@VmtkNFlWVXlTa!pYV0hCWFZsWndSMVF^V@tOVmJFSlZUVVF$UFE9PQ==
pw :Vm0wd@QyUXlVWGxWV0d^V!YwZDRWMVl$WkRSV0!WbDNXa!JTVjAxV@JETlhhMUpUVmpBeFYySkVUbGhoTVVwVVZtcEJlRll&U@tWVWJHaG9UVlZ$VlZacVFtRlRNbEpJVm!0a!dHSkdjRTlaVjNSR!pVWmFkR0&GU@!^U@JHdzFWVEowVjFaWFNraGhSemxWVmpOT00xcFZXbUZrUjA!R!drWndWMDFFUlRGV!ZFb$dWakZhV0ZOcmFHaFNlbXhXVm0xNFlVMHhXbk&YYlVaclVqQTFSMWRyV@xOVWJVcEdZMFZ$VjJKVVJYZFdha!pYWkVaT@MxZHNhR@xTTW!oWlYxZDRiMkl&Vm&OVmJGWlRZbFZhY@xWcVFURlNNVlY!VFZSU!ZrMXJjRWxhU0hCSFZqRmFSbUl*WkZkaGExcG9WakJhVDJOdFJraGhSazVzWWxob!dGWnRNSGhPUm!^V!RVaG9XR0pyTlZsWmJGWmhZMVphZEdSSFJrNVNiRm9$V@xWYVQxWlhTbFpqUldSYVRVWmFNMVpxU@t0V!ZrcFpXa!p$VjFKV@NIbFdWRUpoVkRKT@MyTkZhR$BTYXpWWVZXcE9iMkl^V@&STldHUlZUVlpXTkZVeGFHOWhiRXB*WTBac!dtSkdXbWhaTW&oWFkxWkdWVkpzVGs!WFJVcElWbXBLTkZReFdsaFRhMlJxVW0xNGFGVXdhRU&UUmxweFVtMUdVMkpWYkRaWGExcHJZVWRGZUdOSE9WZGhhMHBvVmtSS!QyUkdTbkpoUjJoVFlYcFdlbGRYZUc&aU!XUkhWMjVTVGxOSGFGQlZiVEUwVmpGU!ZtRkhPVmhTTUhCNVZHeGFjMWR0U@tkWGJXaGFUVzVvV0ZreFdrZFdWa$B*VkdzMVYySkdhM@hXYTFwaFZURlZlRmR!U@s!WFJYQnhWVzB^YjFZeFVsaE9WazVPVFZad@VGVXlkREJXTVZweVkwWndXR0V^Y0ROV@FrWkxWakpPU!dKR!pGZFNWWEJ@Vm!0U!MxUXlUWGxVYTFwb!VqTkNWRmxZY0ZkWFZscFlZMFU!YVUxcmJEUldNV@h@V!ZaS!IxTnNaRlZXYkZwNlZHeGFZVmRGTlZaUFZtaFRUVWhDU@xac!pEUmpNV!IwVTJ0b@FGSnNTbGhVVlZwM!ZrWmFjVk&yWkZOaVJrcDZWa@N^YzFVeVNuSlRiVVpYVFc!b!dGbHFTa!psUm!SWldrVTFWMVpzY0ZWWFZsSkhaREZaZUdKSVNsaGhNMUpVVlcxNGQyVkdWbGRoUnpsb!RWWndlbFl&Y0VkV0!ERjFZVWhLV@xaWFVrZGFWM@hIWTIxS!IyRkdhRlJTVlhCS!ZtMTBVMU!^VlhoWFdHaFlZbXhhVjFsc!pHOVdSbXhaWTBaa@JHSkhVbGxhVldNMVlWVXhXRlZyYUZkTmFsWlVWa@Q0YTFOR!ZuTlhiRlpYWWtoQ!NWWkdVa@RWTVZwMFVtdG9VRll&YUhCVmJHaERUbXhrVlZGdFJtcE&WMUl$VlRKMGExZEhTbGhoUjBaVlZucFdkbFl$V@&KbFJtUnlXa!prVjJFelFqWldhMlI@VFZaWmQwMVdXbWxsYTFwWVdXeG9RMVJHVW&KWGJFcHNVbTFTZWxsVldsTmhWa$AxVVd^d!YySllVbGhhUkVaYVpVZEtTVk&zYUdoTk!VcFdWbGN^TkdReVZrZFdXR$hyVWpCYWNGVnRlSGRsYkZsNVpVaGtXRkl$VmpSWk!GSlBWMjFGZVZWclpHRldNMmhJV!RJeFMxSXhjRWhpUm!oVFZsaENTMVp0TVRCVk!VMTRWbGhvV0ZkSGFGbFpiWGhoVm!^c@NscEhPV$BTYkhCNFZrY$dOVll^V@&OalJXaFlWa!UxZGxsV!ZYaFhSbFp&WVVaa!RtRnNXbFZXYTJRMFdWWktjMVJ!VG!oU@JGcFlXV$hhUm!ReFduRlJiVVphVm0xU!NWWlhkRzloTVVwMFlVWlNWVlpXY0dGVVZscGhZekZ$UlZWdGNFNVdNVWwzVmxSS0!HRXhaRWhUYkdob!VqQmFWbFp0ZUhkTk!WcHlWMjFHYWxacmNEQmFSV!F$VmpKS@NsTnJhRmRTTTJob!ZrUktSMVl^VG&WVmJFSlhVbFJXV!ZaR!l*RmlNV!JIWWtaV!VsZEhhRlJVVm!SVFpXeHNWbGRzVG!oU!ZFWjZWVEkxYjFZeFdYcFZiR@hZVm!^d!lWcFZXbXRrVmtwelZtMXNWMUl*YURWV0!XUXdXVmRSZVZaclpGZGliRXB&Vld0V!MySXhiRmxqUldSc!ZteEtlbFp0TURWWFIwcEhZMFpvV@sxSGFFeFdNbmhoVjBaV@NscEhSbGROTW!oSlYxUkplRk!^U!hoalJXUmhVbXMxV0ZZd!ZrdE&iRnAwWTBWa!dsWXdWalJXYkdodlYwWmtTR0ZHV@xwaVdHaG9WbTE0YzJOc!pISmtSM0JUWWtad0&GWlhNVEJOUmxsNFYyNU9hbEpYYUZoV@FrNVRWRVpzVlZGWWFGTldhM0I@VmtkNFlWVXlTa!pYV0hCWFZsWndSMVF^V@tOVmJFSlZUVVF$UFE9PQ==
17번
<html>
<head>
<title>Challenge 17</title>
</head>
<body bgcolor=black>
<font color=red size=10></font>
<p>
<form name=login>
<input type=passwd name=pw><input type=button onclick=sub() value="check">
</form>
<script>
unlock=100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+1/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10+100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10-100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10/100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10*100*10*10+100/10-10+10+50-9*8+7-6+5-4*3-2*1*10+9999999;
function sub(){ if(login.pw.value==unlock){ location.href="?"+unlock/10; } else{ alert("Wrong"); } }
</script>
unlock 값을 계산하면 되는데 콘솔에 치면 그냥 나온다.
24번
<?php
include "../../config.php";
if($_GET['view_source']) view_source();
?><html>
<head>
<title>Challenge 24</title>
</head>
<body>
<p>
<?php
extract($_SERVER);
extract($_COOKIE);
$ip = $REMOTE_ADDR;
$agent = $HTTP_USER_AGENT;
if($REMOTE_ADDR){
$ip = htmlspecialchars($REMOTE_ADDR);
$ip = str_replace("..",".",$ip);
$ip = str_replace("12","",$ip);
$ip = str_replace("7.","",$ip);
$ip = str_replace("0.","",$ip);
}
if($HTTP_USER_AGENT){
$agent=htmlspecialchars($HTTP_USER_AGENT);
}
echo "<table border=1><tr><td>client ip</td><td>{$ip}</td></tr><tr><td>agent</td><td>{$agent}</td></tr></table>";
if($ip=="127.0.0.1"){
solve(24);
exit();
}
else{
echo "<hr><center>Wrong IP!</center>";
}
?><hr>
<a href=?view_source=1>view-source</a>
</body>
</html>ip를 127.0.0.1 로 세팅해주면 풀리는 문제이다. 이 문제는 extract 함수의 취약점을 이용하는 문제이다. extract 는 array를 변수로 세팅해준다. 이걸 array라고 불러야 할지 map이라고 해야할지 잘 모르겠는데.. 쿠키에 ip 를 세팅해주고 저 str_replace를 잘 우회해주면 된다.
39번
<?php
include "../../config.php";
if($_GET['view_source']) view_source();
?><html>
<head>
<title>Chellenge 39</title>
</head>
<body>
<?php
$db = dbconnect();
if($_POST['id']){
$_POST['id'] = str_replace("\\","",$_POST['id']);
$_POST['id'] = str_replace("'","''",$_POST['id']);
$_POST['id'] = substr($_POST['id'],0,15);
$result = mysqli_fetch_array(mysqli_query($db,"select 1 from member where length(id)<14 and id='{$_POST['id']}"));
if($result[0] == 1){
solve(39);
}
}
?>
<form method=post action=index.php>
<input type=text name=id maxlength=15 size=30>
<input type=submit>
</form>
<a href=?view_source=1>view-source</a>
</body>
</html>
' 가 제대로 안닫혀있어서 substr 우회를 위해 공백문자로 14까지 채운뒤 15자리에 ' 을 입력해주자.
쉬운 sql injection이다.
58번
