Cybertalents Quals : Saudi, Sudan, Egypt and Tunisia National CTF 2020 Write-Up
Hi , My name is Ahmed Magdy
This is frist write-up for my
Let’s go……
General Information
After search in (( al4y5 Google ))
The answer >> “ macro virus ” but the answer to submit “ macro ”
Let’s go solving the web challenge
1- Pr0mo ( Easy )
I don’t find any button so check the sourse code and i don’t find any thing again so
I check in case i find the cookies
I find this cookies
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoiZ3Vlc3QifQ.-HH8XJLZbewaxQQkraUukPpThcOG9LUSIq7gxhlMF6s
After search in (( al4y5 google )) I find two attack in jwt
one of them Cracker Signature
So i use the tool jwt-secret
I find the secret key (123123)
and change the user from “guest” to “admin”
And i use the storage in tool inspet element and edite the new cookies
it is BrainFuck language .. So Let’s decode it
go to This website to decode the string
Flag: FLAG{JWT_I_Lik3_iT}
2-Red Alert 2.0 ( easy )
I check the sourse code and i find the js code but i don’t understand it at frist
so i tried the XSS Alert Payload
I tried <img src=1 onerror=alert(1)> but the payload not give my the alert but print the fake img
And i tried <video><source onerror=”alert(1)”> the payload give my the alert but don’t give my the flag
So i go to read the js code again and search in (( al4y5 Google )) about the Mutation XSS
I find the write-up for XSS in Google and find the payload
<noscript onkeyup=”alert(1)” contenteditable></noscript>
Flag: FLAG{Go0Gl3_XSs_XD}
3- Mystery (Medium)
I’m openning the source code, I find this herf MD5 hash
I tried decode it and I find meaning ( 1 ,, 5 ,, 66 )
So i’m makeing file have MD5 hash from (1) to (100) number and brute-force numbers with burp-suite and check the status (200)
the number 43 with status (200) and with a hash value “17e62166fc8586dfa4d1bc0e1742c08b” find the flag with it
Flag: flag{MD5-N0T-1337}
Digital Forensics
1- Images3c (Easy)
Download the file and unzip
I find this img :
I use the tool name steghide to check if the img have hide file
I find the file but i need pass for read it
I use the StegCracker to read it and use the wordlist handlin to crack the pass
The pass >> 1234
And your hide file name is cyber.jpg.out
Flag: flag{cyb3rs3cisaw3s0me}
Think you for your time
And finally, Thank you to read this writeup :D