2020weight 100.000ops

0CTF/TCTF 2020 Finals

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

Binary exploitation3

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 finder Shellcode assembler and library Cyclic pattern generator and offset finder Format string exploit builder Learn: Binary exploitation

babyheap
485 pts1 writeup
- pwn
- heap
Same technique in picoCTF: tea-cash, sice_cream, zero_to_hero
Emoji Revenge
1000 pts1 writeup
- unicode
- glibc
- pwn
Same technique in picoCTF: Guessing Game 1, x-sixty-what, format string 3
SecureEnv
733 pts1 writeup
- shellcode
- sgx
- pwn
Same technique in picoCTF: Binary Gauntlet 2, ropfu, solfire

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

Oblivious
478 pts1 writeup
- rsa
- crypto
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle

Binary exploitation3

babyheap

Emoji Revenge

SecureEnv

Cryptography1

Oblivious

Other 2020 events