[NahamCon CTF 2020] Web Exploitation WriteUp !

Hello guys ! Long time no write !
Today , I come back to my blog with NahamCon CTF which is held about 1 week ago.
I had solved some web challenges and absorbed many things useful 👅
Let's start!

[Root-Me] JWT Revoked Token

Hi guys , after nearly 2 months dont care about Root Me challenges , I come back to it and realize that some challenges have been added to Web Serveur catalog recently . I decide to play with JWT again . 😃

25 Points , not too much hard  , huh? I though so . And after solved this chall , I have to say : " It's not really hard , but so much tricky" . Let's see !

[PenTest] L*G.vn XSS detecting and exploiting!

Hi ,
Today, I will show you some interesting stuff which I have just done .
My friend want to buy a backpack from this website, she sent web address to me and asked me how the backpack was .

I dont really care about backpack.
In my vision, the only thing exist is the search engine on the left side.

[Securinets] Writeup jeopardy !

Hi guys.
Corona Virus aka Covid-19 has spreaded all over the world , we much #stayhome to protect our shelves . So , I have very much time to learning and training my hacking skill . This month ,with my team, I has participated in Securinets ctf competition . Very interesing , it has many , many things to discuss . Here is the result .

[WRITEUP] XML EXTERNAL ENTITY (XXE) INJECTION ROOTME

AFTER TET HOLIDAYS, WE FACE TO THE CORONA(2019-nCoV) VIRUS ,SO WE MUST PROTECT OURSELVES AND LIMIT TO GO TO PUBLIC PLACE . AS A OPTIMIST, IT'S MY RELAXING TIME TO CONTINUE TO SOLVE ROOT-ME CHALLENGE 😃 . TODAY , WE HAVE XXE INJECTION . LET'S START!

[wargame.kr&rootme] PHP TYPE CONFUSION & LOOSE COMPARISON WRITEUP!

FIRST OF ALL , WE SHOULD FOCUS ON THE DEFINITION

A loose comparison is one performed using two equals signs (==).It follows suit with the “best-guess” approach, which can lead to some unexpected results. 

TAKE A LOOK INTO THIS TABLE

[WARGAME.KR] MD5 PASSWORD VULNERABILITY WRITEUP!

THIS CHALL IS TO SUBMIT A PASSWORD WHICH WILL BE SENT TO md5($ps,true) FUNCTION AND THIS MD5 PASSWORD IS A PART OF THIS SQL QUERY :

$row=@mysql_fetch_array(mysql_query("select * from admin_password where password='".md5($ps,true)."'"));

OFCORSE WE DONT HAVE IDEA ABOUT PASSWORD , SO WE MUST FIND A WAY TO BYPASS THIS QUERY BY SQL INJECTION !

FIRST, TAKE A LOOK AT MD5() FUNCTION DEFINITION AND IT'S VULENERABILITY :

 string md5 ( string $str , [ bool $raw_output = false ] )

[WRITEUP] SQL INJECTION -ROUTED ROOTME

THEO ĐÁNH GIÁ CHỦ QUAN , CHALL NÀY KHÔNG QUÁ KHÓ , NHƯNG MỚI LẠ Ở CÁCH TIẾP CẬN VÀ THỰC THI QUERY
TRONG BÀI NÀY MÌNH SẼ KHÔNG GHI RÕ NHỮNG CÂU QUERY RA , CHỈ SHOW KẾT QUẢ VÀ CÁC BƯỚC CƠ BẢN ĐỂ THỰC THI :D



MỞ ĐẦU CHALL LÀ FORM KHÁ QUEN THUỘC , ĐỪNG AI DẠI DỘT FUZZ VÀO CÁI FORM NÀY NHÉ :D . CHUYỂN QUA TRANG "SEARCH" ĐI !

[WRITEUP] SQL INJECTION - STRING ROOTME

SAU KHI CAY ĐẮNG BỎ QUA BÀI SQL INJECTION GBK KHÔNG LÀM ĐƯỢC( MẶC DÙ ĐÃ NẮM LÝ THUYẾT VÀ THI TRIỂN HẾT CÔNG LỰC) , ĐÀNH PHẢI GẠT NƯỚC MẮT QUA VÀ TIẾP TỤC
NHÌN QUA CHALL

SQL INJECTION MÀ , QUA PAGE LOGIN NGÓ TÍ
 

  

[picoCTF2019][WEB EXPLOITATION] WRITE-UP !

SO , THIS IS VERY FIRST TIME MY NEW TEAM TAKE PART IN A CTF COMPETITION [PICOCTF]




I MAKE THIS WRITE-UP AS THE NOTE FOR ALL WEB-CHALLENGE I HAD SOLVED THROUGH PICOCTF COMPETITION