Pwncry - InCTF Internationals 2020 rudyerudite 2020-08-09 Pwn / Linux / ELF tl;dr Passing corrupted ciphertext to get the symmetric key leak Fastbin link corruption Exploiting double free and UAF in the heap Read More InCTFi
Secret Service - InCTF Internationals 2020 Cyb0rG 2020-08-06 Pwn / Exploitation tl;dr Use format String to get into secret service. Get libc leaks by overwriting mapped bit of a free chunk. Overwrite the Thread Local Block , thus overwriting canary to get buffer overflow. Read More InCTFi Format String TCB overwrite Calloc Malefacerum
LOGarithm - InCTF Internationals 2020 stuxn3t 2020-08-04 Forensics / Memory tl;dr Extract keylogger script from the memory dump. Extract the master key from the packet capture. Reverse the script to get the flag. Read More InCTFi Windows Memory Analysis
No Shake - InCTF Internationals 2020 m0n574 2020-08-04 Web Exploitation / TLS tl;dr Extract key from the admin by STARTTLS downgrade on the message Deserialize using references to get next phase Deserialization to RCE to get flag Read More
Investigation Continues - InCTF Internationals 2020 stuxn3t 2020-08-04 Forensics / Memory tl;dr Extract Invalid Login timestamp from the windows registry. Extract the timestamp of when a JPEG was opened. Extract Google Chrome’s last run time which was pinned to taskbar from windows registry. Read More InCTFi Volatility Windows Memory Analysis Windows Registry
Investigation - InCTF Internationals 2020 stuxn3t 2020-08-04 Forensics / Memory tl;dr Extract process last run time from the windows registry. Extract process run count from the windows registry. Read More InCTFi Volatility Windows Memory Analysis Windows Registry
Lookout Foxy - InCTF Internationals 2020 g4rud4 2020-08-03 Forensics / Disk tl;dr Decrypt the encrypted GPG file found in Outlook Express with the private key stored on the device. Decrypt the firefox saved passwords and log in to the website that the terrorist used. Read More InCTFi Autopsy
Faulty LFSR - InCTF Internationals 2020 ph03n1x 2020-08-02 Crypto / LFSR tl;dr Find the co-relation between variables in the LFSR equation d == out (75%) a == b (75%) c^d == out (75%) (d!= out) => (c==1) always Solve for the seed using 2000 output bits Try out which among the four possible combinations decrypt the flag Read More InCTFi LFSR Correlation attack
BabyJS - 2020 Defenit CTF Az3z3l 2020-06-10 Web Exploitation tl;dr Accessing a variable in Handlebars template using this object Read More Defenit Handlebars template injection Ssti
TarAnalyzer - 2020 Defenit CTF c3rb3ru5 2020-06-07 Web Exploitation tl;dr Zip Slip Vulnerability + YAML Deserialization Attack + Race Condition Unintended Solution: Upload symlink leading to arbitarary file reads Read More Defenit YAML Zip Slip Race Condition Symlink