Still Meta

Find the flag.

Flag Format: CIT{example_flag}

If you cannot solve this challenge using PUC Lua, try using LuaJIT instead.

by ronnie

Given a file stillmeta.lua, we can see that the file is a Lua script. The script contains a lot of obfuscated code, but it also contains some hints about the flag.

function(N,X)local f=g(X)local E=function(E,m,d,J)return G(N,{E;m,d,J},X,f)end return E end,{}return(W(630955+12938805,{}))(f(P))end)(getfenv and getfenv()or _ENV,unpack or table[X((-394860-(-807224))+-430539)],newproxy,setmetatable,getmetatable,select,{...})end)(...)

The script is obfuscated, but we can see that it uses some functions like getfenv, unpack, newproxy, setmetatable, and getmetatable. These functions are used to manipulate the Lua environment and create new objects.

Based on ChatGPT’s explanation, the script is trying to create a new environment and execute some code in that environment.

Instead of manually reversing the obfuscated code, we can safely load and inspect the script’s global variables to find the flag.

local ok, result = pcall(dofile, "stillmeta.lua")
if not ok then
  print("Error loading stillmeta.lua: " .. result)
  return
end

for k, v in pairs(_G) do
  if type(v) == "string" and v:find("CIT{") then
    print(k .. ": " .. v)
  end
end