justCTF 2025
23 challenges with 8 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. 17 of them also carry the solution justCTF 2025’s own organisers published, which is linked on the challenge itself.
Full task list on CTFtimeUncategorised20
The upstream scoreboard did not say, so neither do we.
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/mallory.py, private/private/solver/run.sh, private/private/solver/solve_crypto.py
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/exploit.py, private/private/solver/run.sh, private/public/exploit.py
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/solve.py, private/private/solver/solve.sh, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/Readme.md, private/private/solve.py, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/solver/README.md, private/solver/test.sh, private/solver/xss-v3.3.6.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/run.sh, private/private/solver/solve.x86_64.S
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py, private/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/solver/README.md, private/solver/solver.py
Babyheap
1 official solutionAlso written up in: iilegacyyii/Writeups
Chapter 1
1 official solutionAlso written up in: blog.davidherm.es
Chapter 2
1 official solutionAlso written up in: blog.davidherm.es
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solver/solve.sh
Published by the organisers in justcatthefish/justctf-2025: private/private/solve.py
Published by the organisers in justcatthefish/justctf-2025: private/private/solver.py
Published by the organisers in justcatthefish/justctf-2025: private/solver/exploit-server.js
Reverse engineering2
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
- re
Same technique in picoCTF: Checkpass, WinAntiDbg0x100, WinAntiDbg0x200
Baby Goes Re
1 official solutionAlso written up in: Usupek/ctf-writeups
Misc1
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
- prototype-pollution
- node.js
Same technique in picoCTF: PW Crack 2, Permissions, Specialer