2021from public repositories
CyberSanta21 2021
12 challenges with 12 published solutions between them. CTFtime has no listing for this event at all, so nothing built on CTFtime can show what it was made of. These writeups were found in public repositories instead. Each link is pinned to the commit it was read from.
Where these writeups liveCryptography5
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 decoderVigenere cipher solver with automatic key recoveryRSA decryption and attack runnerWiener’s attack on small RSA private exponentsIn-browser hash cracker with rule transformsLearn: Classical ciphers and frequency analysisLearn: RSA and the parameters that break it
Common Mistake
1 official solutionMeet Me Halfway
1 official solutionMissing Reindeer
1 official solutionWarehouse Maintenance
1 official solutionXmas Spirit
1 official solution
Web5
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 verifierJWT alg=none bypass generatorWeb attack payload catalogJWT secret brute forceLearn: Web attacks and session tokens
Elf Directory
1 official solutionGadget Santa
1 official solutionNaughty or Nice
1 official solutionToy Management
1 official solutionToy Workshop
1 official solution
Binary exploitation2
Turn a memory-safety bug in a native binary into control of execution. Usually a stack overflow, a format string, or a heap primitive.
Solve it with:ROP gadget finderShellcode assembler and libraryCyclic pattern generator and offset finderFormat string exploit builderLearn: Binary exploitation
Mr Snowy
1 official solutionSleigh
1 official solution