2019weight 20.00CCSIR.org

DefCamp CTF Finals 2019

4 challenges with 4 published community solutions between them. Solution links go to CTFtime’s task page, which aggregates every writeup for a challenge - individual blog posts rot, the aggregator does not.

Full task list on CTFtime

Misc2

Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.

Solve it with:Brainfuck and esolang decoder Cipher identifier and automatic decoder Regex tester with match offsets and capture groups Learn: Recognising encodings

Simple notes
50 pts1 writeup
- command-injection
Same technique in picoCTF: Permissions, Specialer, Codebook
Treasure map
136 pts1 writeup
- pdf
Same technique in picoCTF: Permissions, Specialer, Codebook

Cryptography1

Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.

Solve it with:Cipher identifier and automatic decoder Vigenere cipher solver with automatic key recovery RSA decryption and attack runner Wiener’s attack on small RSA private exponents In-browser hash cracker with rule transforms Learn: Classical ciphers and frequency analysis Learn: RSA and the parameters that break it

Crypto
136 pts1 writeup
- xor
Same technique in picoCTF: Custom encryption, triple-secure, XtraORdinary

Web1

Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.

Solve it with:JWT decoder and signature verifier JWT alg=none bypass generator Web attack payload catalog JWT secret brute force Learn: Web attacks and session tokens

Lucky
304 pts1 writeup
- http
- guessing
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3

Misc2

Simple notes

Treasure map

Cryptography1

Crypto

Web1

Lucky

Other 2019 events