2025weight 67.32LIT CTF

Lexington Informatics Tournament CTF 2025

4 challenges with 5 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

Web3

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

web/group chat
164 pts2 writeups
- flask
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
web/group chat2
198 pts1 writeup
- flask
- ssti
- web
Same technique in picoCTF: Bithug, Startup Company, SSTI2
web/my-first-website
186 pts1 writeup
- flask
- sql-injection
- web
- command_injection
- stored-xss
Same technique in picoCTF: Irish-Name-Repo 3, More SQLi, Secret Box

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/encryption two ways
130 pts1 writeup
- rsa
- crypto
- xor
Same technique in picoCTF: StegoRSA, john_pollard, Custom encryption

Web3

web/group chat

web/group chat2

web/my-first-website

Cryptography1

crypto/encryption two ways

Other 2025 events