REA team@REA team
Use REA to solve DownUnderCTF's masked squares flag checker. Find the checking functions, extract the masks and compare a recovered flag with the original program.
Website · by REA team
Solving a CTF flag checker
Inspects a DownUnderCTF binary, finds its checking functions, turns the masks and sums into equations and confirms the solved flag against the original program.
About this case
Inspects a DownUnderCTF binary, finds its checking functions, turns the masks and sums into equations and confirms the solved flag against the original program.
Why it is listed: A CTF challenge: the intended, legitimate use.
Setup
See the original source for installation instructions.
Original text / README
Use REA to solve DownUnderCTF's masked squares flag checker. Find the checking functions, extract the masks and compare a recovered flag with the original program.
Similar projects
NullLabTests@NullLabTests
A static analysis write-up of Ubuntu's netcat-openbsd binary using REA with Ghidra, with the evidence behind each finding.
OpenBSD netcat, analysed with REA and Ghidra
Stars 3
jinshi666888@jinshi666888
A hands-on teaching playbook using a minimal Electron target: extract evidence with file and line references, probe the MCP server and recreate the feature.
rea-playbook: from evidence to file:line to recreation
Stars 1
jkf87@jkf87
Follow-along exercises from a Korean video: build your own small Electron app and C program, then analyse them with REA, Ghidra and Claude Code.
Hands-on: analysing your own apps with REA, Ghidra and Claude Code
Stars 1