2023weight 34.17SavedByTheShell

UMass CTF 2023

5 challenges with 6 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

Web2

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

DeepFried
100 pts2 writeups
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
umassdining2
477 pts1 writeup
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3

Reverse engineering2

Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.

Solve it with:Strings extractor for binaries and blobs WebAssembly disassembler Java .class disassembler Python .pyc bytecode disassembler Learn: Binary exploitation

java_jitters
499 pts1 writeup
- rev
Same technique in picoCTF: vault-door-1, vault-door-3, vault-door-4
java_jitters_v2
500 pts1 writeup
- rev
Same technique in picoCTF: vault-door-1, vault-door-3, vault-door-4

Misc1

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

csgo_but_decentralised
490 pts1 writeup
- blockchain
Same technique in picoCTF: Reentrance, Smart_Overflow, Access_Control

Web2

DeepFried

umassdining2

Reverse engineering2

java_jitters

java_jitters_v2

Misc1

csgo_but_decentralised

Other 2023 events