Microsoft Edge Chakra JIT - Scope Parsing Type Confusion Exploit

Exploit for windows platform in category dos / poc // PoC: async function triggera = class b await 1 let spray = ; for let i = 0; i 0016 SetHomeObj R13 R14 001b NewScObjectSimple R9 001d ProfiledStFld R9.value = R2 1 0021 ProfiledStFld R9.done = R4 2 0025 Yield R9 R9...

Microsoft Edge Chakra JIT - DictionaryPropertyDescriptor::CopyFrom Type Confusion

Microsoft Edge Chakra JIT - DictionaryPropertyDescriptor::CopyFrom Type Confusion / Here's the method. template template void DictionaryPropertyDescriptor::CopyFromDictionaryPropertyDescriptor& descriptor this-Attributes = descriptor.Attributes; this-Data = descriptor.Data ==...

Microsoft Edge Chakra JIT - Magic Value Type Confusion

Microsoft Edge Chakra JIT - Magic Value Type Confusion / BOOL JavascriptNativeFloatArray::SetItemuint32 index, double dValue if uint64&dValue == uint64&JavascriptNativeFloatArray::MissingItem JavascriptArray varArr = JavascriptNativeFloatArray::ToVarArraythis; varArr-DirectSetItemAtindex,...

Microsoft Edge Chakra JIT CallRegExSymbolFunction Return Check Fail Exploit

Exploit for windows platform in category dos / poc Microsoft Edge: Chakra: JIT: CallRegExSymbolFunction doesn't check the return type The "CallRegExSymbolFunction" method is used to call symbol functions in regexp objects. But it doesn't check the return value's type. Since the user can define th...

Microsoft Edge Chakra JIT - NewScObjectNoCtor Array Type Confusion

Microsoft Edge Chakra JIT - NewScObjectNoCtor Array Type Confusion / This is similar to the previous issues 1457, 1459 MSRC 42551, MSRC 42552. If a JavaScript function is used as a consturctor, it sets the new object's "proto" to its "prototype". The JIT compiler uses NewScObjectNoCtor instructio...

Microsoft Edge Chakra JIT - Array.prototype.reverse Array Type Confusion Exploit

Exploit for windows platform in category dos / poc / This is simillar to the previous issue 1457. But this time, we use Array.prototype.reverse. Array.prototype.reverse can be inlined and may invoke EnsureNonNativeArray to convert the prototype of "this" to a Var array. Call flow:...

Microsoft Edge Chakra JIT - ImplicitCallFlags Checks Bypass

Microsoft Edge Chakra JIT - ImplicitCallFlags Checks Bypass / Here's a snippet of ExecuteImplicitCall which is responsible for updating the ImplicitCallFlags flag. template inline Js::Var ExecuteImplicitCallJs::RecyclableObject function, Js::ImplicitCallFlags flags, Fn implicitCall...

Microsoft Edge Chakra JIT - Array Type Confusion via InitProto Instructions

/ If a native array is used as a prototype, it is converted to a Var array by the Js::JavascriptNativeFloatArray::SetIsPrototype method. In the JIT compiler, it uses InitProto instructions to set object literals' prototype. But when optimizing those instructions, it doesn't reset the previous arr...

Microsoft Edge Chakra JIT - GlobOpt::OptTagChecks Must Consider IsLoopPrePass Properly (2)

Microsoft Edge Chakra JIT - GlobOpt::OptTagChecks Must Consider IsLoopPrePass Properly 2 It seems this is the patch for the bug. https://github.com/Microsoft/ChakraCore/pull/4226/commits/874551dd00ff6f404e593c7e0162efb54b953f5a The following two cases will bypass the fix. 1: function opt let obj ...

Microsoft Edge Chakra JIT - Stack-to-Heap Copy Exploit

Exploit for windows platform in category dos / poc / If variables don't escape the scope, the variables can be allocated to the stack. However, there are some situations, such as when a bailout happens or accessing to arguments containing stack-allocated variables, where those variables should no...

Microsoft Edge Chakra JIT - Out-of-Bounds Write

Microsoft Edge Chakra JIT - Out-of-Bounds Write // Here's the PoC demonstrating OOB write. function optarr, start, end for let i = start; i end; i++ if i === 10 i += 0; // -- a arri = 2.3023e-320; function main let arr = new Array100; arr.fill1.1; for let i = 0; i 1000; i++ optarr, 0, 3; optarr, ...

Microsoft Edge Chakra JIT - 'Lowerer::LowerSetConcatStrMultiItem' Missing Integer Overflow Check

/ The method "Lowerer::LowerSetConcatStrMultiItem" is used to generate machine code to concatenate strings. Here's a snippet of the method. void Lowerer::LowerSetConcatStrMultiItemIR::Instr instr ... IR::IndirOpnd dstLength = IR::IndirOpnd::NewconcatStrOpnd,...

Microsoft Edge Chakra JIT - Lowerer::LowerBoundCheck Incorrect Integer Overflow Check Exploit

Exploit for windows platform in category dos / poc / Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1343 Here's a snippet of the method. void Lowerer::LowerBoundCheckIR::Instr const instr ... ifrightOpnd-IsIntConstOpnd IntConstType newOffset; if!IntConstMath::Addoffset,...

Microsoft Edge Chakra JIT - RegexHelper::StringReplace Must Call the Callback Function with Updating ImplicitCallFlags

Microsoft Edge Chakra JIT - RegexHelper::StringReplace Must Call the Callback Function with Updating ImplicitCallFlags / Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1334 The "String.prototype.replace" method can be inlined in the JIT process. So in the method, all the calls...