atx0mg's Fortress.

MetaCTF 2021

Word count: 481Reading time: 3 min
2021/12/06

TL;DR Just jump to the conclusion at last part if you think this write-up is too lengthy →

Cryptography

Thnks fr th Pwds

Description:


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  • It seems to be encoded as base64, so I decoded it in the following command
    • echo "TWV0YUNURntlbmNvZGluZ19pc19OMFRfdGhlX3NhbWVfYXNfZW5jcnlwdGlvbiEhfQ==" | base64 -d
    • Got flag:

  • MetaCTF{encoding_is_N0T_the_same_as_encryption!!}

    Wrong Way on a One Way Street

    Description:

  • Find the hash with online cracking tools and get:
    • Got flag:

  • MetaCTF{babyloka13}

    Size Matters

    Description:

  • Find the RSA with online cracking tools and get:
    • Got flag:

  • MetaCTF{you_broke_rsa!}

    Forensics

    Magic in the Hex

    Description:

  • Found the magic number of the VMDK file by googling

Got flag:

  • KDM

    Sharing Files and Passwords

    Description:

  • Download the pcap file and filter the FTP protocol and the password revealed
    • Got flag:

  • METACTF{ftp_is_better_than_dropbox}

    Still Believe in Magic?

    Description:

  • Got a file, and when file magic.tar.gz, We got:
    1
    magic.tar.gz: gzip compressed data, last modified: Fri Dec  3 16:51:29 2021, from Unix, original size modulo 2^32 10240
    • It seems the flag is compressed in two kinds of methods (.tar and .gz), so we have to decompress it.
      • So first, I used gzip -d magic.tar.gz to get magic.tar.
      • And then, I used tar -xf magic.tar to get magic.
        • from file magic, we can know magic: Zip archive data, at least v2.0 to extract.
      • Lastly, I used unzip magic to get the magic file
      • cat flag
        • Got flag:

  • MetaCTF{was_it_a_magic_trick_or_magic_bytes?}

    Referece

  • How to decompress files in gzip
  • How to decompress files in tar

    Other

    This Ain't a Scene, It's an Encryption Race

    Description:

  • Find the Mitre ATT&CK technique ID for the encryption of data by googling
    • Got flag:

  • T1486

    Reconnaissance

    Sugar, We're Goin Up

    Description:

  • Found that by googling
    • Got flag:

  • CVE-2021-22205

    The Best Laid Plans...

    Description:

  • Found that by googling
    • Got flag:

  • MetaCTF{Ipv4pReceiveRoutingHeader}

    Who Broke the Printer This Time?

    Description:

  • Found that by googling
    • Got flag:

  • CVE-2021-34527

    Web Exploitation

    Under Inspection

    Description:

  • There is an easy login-page
  • I try to look around the Network by Developer’s tools and find something interesting:
      • From the code, you can tell that if username == "Jazz", the flag will return, so I did.
      • Actually, the password is the flag

        Got flag:

  • MetaCTF{do_it_with_style_or_dont_do_it_at_all}

    Conclusion for this semester (ASU CSE 466)

    Fun

  • Although this is the last CTF game playing with the team ToInfinityAndBeYANd, I had a lot of fun. Thank you all for playing CTF with me this semester. Plus, thank you Yan for providing this great opportunity for us to play CTF this whole semester. Have a lot of fun. Thanks! I’ll keep pushing until I get the yellow belt (even the blue belt)! LOL

    Shout out to all the teammates!

    We had a team called Hacker in discord

I solved 11 challenges, quite a fun one

Author:atx0mg

Link:https://jeff14994.github.io/2021/12/06/MetaCTF-2021/

Publish date:December 6th 2021, 9:17:53 pm

Update date:April 22nd 2022, 5:16:26 am

License:This article is licensed under CC BY-NC 4.0

CATALOG
  1. 1. Cryptography
    1. 1.1. Thnks fr th Pwds
      1. 1.1.1. Description:
      2. 1.1.2. Got flag:
    2. 1.2. Wrong Way on a One Way Street
      1. 1.2.1. Description:
      2. 1.2.2. Got flag:
    3. 1.3. Size Matters
      1. 1.3.1. Description:
      2. 1.3.2. Got flag:
  2. 2. Forensics
    1. 2.1. Magic in the Hex
      1. 2.1.1. Description:
      2. 2.1.2. Got flag:
    2. 2.2. Sharing Files and Passwords
      1. 2.2.1. Description:
      2. 2.2.2. Got flag:
    3. 2.3. Still Believe in Magic?
      1. 2.3.1. Description:
      2. 2.3.2. Got flag:
      3. 2.3.3. Referece
  3. 3. Other
    1. 3.1. This Ain't a Scene, It's an Encryption Race
      1. 3.1.1. Description:
      2. 3.1.2. Got flag:
  4. 4. Reconnaissance
    1. 4.1. Sugar, We're Goin Up
      1. 4.1.1. Description:
      2. 4.1.2. Got flag:
    2. 4.2. The Best Laid Plans...
      1. 4.2.1. Description:
      2. 4.2.2. Got flag:
    3. 4.3. Who Broke the Printer This Time?
      1. 4.3.1. Description:
      2. 4.3.2. Got flag:
  5. 5. Web Exploitation
    1. 5.1. Under Inspection
      1. 5.1.1. Description:
      2. 5.1.2. Got flag:
  6. 6. Conclusion for this semester (ASU CSE 466)
    1. 6.0.1. Fun
    2. 6.0.2. Shout out to all the teammates!
    3. 6.0.3. We had a team called Hacker in discord
    4. 6.0.4. I solved 11 challenges, quite a fun one