CSAW_CTF_Quals_2021.md

CSAW CTF Qualification Round 2021

• We (OctaC0re) have ranked 98th (out of ~1200 teams) worldwide.

---

PoemCollection

Hey! I made a cool website that shows off my favorite poems. See if you can find flag.txt somewhere!

http://web.chal.csaw.io:5003

Just changed the GET argument to "../flag.txt"

http://web.chal.csaw.io:5003/poems/?poem=../flag.txt -> and there you go: flag{l0c4l_f1l3_1nclusi0n_f0r_7h3_w1n}

---

Crack Me

Can you crack this?
Your hash: a60458d2180258d47d7f7bef5236b33e86711ac926518ca4545ebf24cdc0b76c.
Your salt: the encryption method of the hash.
(So if the hash is of the word example, you would submit flag{example} to score points.)

after identifying with hash-identifier we identify it's sha256 with salt so we go on it using the sha256($salt.$pass) mode:

hashcat -m 1420 a60458d2180258d47d7f7bef5236b33e86711ac926518ca4545ebf24cdc0b76c:sha256 rockme.txt

• we find the following:

    a60458d2180258d47d7f7bef5236b33e86711ac926518ca4545ebf24cdc0b76c:sha256:cathouse
  
    Session..........: hashcat
    Status...........: Cracked
    Hash.Name........: sha256($salt.$pass)
  

-> So obviously I submitted the following: flag{cathouse}

---

Weak Password

Can you crack Aaron’s password hash?
He seems to like simple passwords.I’m sure he’ll use his name and birthday in it.
Hint: Aaron writes important dates as YYYYMMDD rather than YYYY-MM-DD or any other special character separator.
Once you crack the password, prepend it with flag{ and append it with } to submit the flag with our standard format.

Hash: 7f4986da7d7b52fa81f98278e6ec9dcb

• After running Hashid & 'hash-identifier' both leads us to MD5, so I had to run hashcat with md5($salt.$pass) Mode

hashcat -a 0 -m 20 7f4986da7d7b52fa81f98278e6ec9dcb:Aaron rockme.txt

we find the following after some attempts: 7f4986da7d7b52fa81f98278e6ec9dcb:Aaron:19800321

-> Then I easily submitted the following: flag{Aaron19800321}

---

• Those challenges are solved by Amdj3dax with OctaC0re team.