CVE-2025-43529

CVE-2025-43529 TL; DR Apple 最近发布了 iOS 26.2 和 iPadOS 26.2，以及一份安全公告，其中包含对 WebKit 漏洞的修复。DFG JIT 编译器中的一个 bug（CVE-2025-43529）引起了我的注意，所以我决定深入研究它。 JIT 编译器正确地识别出 Phi 节点（多个控制流路径合并处）已经逃逸，但未能注意到 Phi 的 Upsilon 节点也已逃逸。因此，DFG 编译的 StoreBarrierInsertionPhase 跳过了插入 Store Barrier，而 Store Barrier 是一种关键的内存安全机制。结果，并发...

DFG JIT Use-After-Free

DFG's doesGC is incorrect about the HasIndexedProperty operation's behavior on StringObjects. This can lead to a use-after-free condition. See also https://bugs.chromium.org/p/project-zero/issues/detail?id=1699 for a similar issue. The DFG JIT compiler attempts to determine whether a DFG IR...

Apple Safari DFG JIT Use-After-Free Information Disclosure Vulnerability

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Apple Safari. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the DFG JIT...

Apple macOS < 10.14.5 / iOS < 12.3 JavaScriptCore - Loop-Invariant Code Motion (LICM) in DFG JIT Leaves Stack Variable Uninitialized

While fuzzing JavaScriptCore, I encountered the following modified and commented JavaScript program which crashes jsc from current HEAD and release: // Run with --useConcurrentJIT=false // Fill the stack with the return value of the provided function. function stacksprayf // This function will...

Apple macOS 10.14.5 iOS 12.3 DFG JIT Compiler - HasIndexedProperty Use-After-Free

Apple macOS 10.14.5 iOS 12.3 DFG JIT Compiler - HasIndexedProperty Use-After-Free See also https://bugs.chromium.org/p/project-zero/issues/detail?id=1699 for a similar issue. The DFG JIT compiler attempts to determine whether a DFG IR operation could cause garbage collection GC during its executi...

macOS < 10.14.5 / iOS < 12.3 DFG JIT Compiler - HasIndexedProperty Use-After-Free Exploit

macOS 10.14.5 / iOS 12.3 DFG JIT Compiler - HasIndexedProperty Use-After-Free Exploit See also https://bugs.chromium.org/p/project-zero/issues/detail?id=1699 for a similar issue. The DFG JIT compiler attempts to determine whether a DFG IR operation could cause garbage collection GC during its...

macOS < 10.14.5 / iOS < 12.3 JavaScriptCore - Loop-Invariant Code Motion (LICM) in DFG JIT

macOS 13.37; stackspray = ; for let v15 = 0; v15 100; v15++ function v19v23 // This weird loop form might be required to prevent loop unrolling... for let v30 = 0; v30 3; v30 = v30 + "asdf" // Generates the specific CFG necessary to trigger the bug. const v33 = Error != Error; if v33 else // Forc...

Apple macOS < 10.14.5 / iOS < 12.3 DFG JIT Compiler - 'HasIndexedProperty' Use-After-Free

See also https://bugs.chromium.org/p/project-zero/issues/detail?id=1699 for a similar issue. The DFG JIT compiler attempts to determine whether a DFG IR operation could cause garbage collection GC during its execution 1. With this, it is then possible for the compiler to determine whether there...

Apple macOS 10.14.5 iOS 12.3 JavaScriptCore - Loop-Invariant Code Motion (LICM) in DFG JIT Leaves Stack Variable Uninitialized

Apple macOS 10.14.5 iOS 12.3 JavaScriptCore - Loop-Invariant Code Motion LICM in DFG JIT Leaves Stack Variable Uninitialized While fuzzing JavaScriptCore, I encountered the following modified and commented JavaScript program which crashes jsc from current HEAD and release: // Run with...

Safari+macOS full exploit chain-vulnerability and early warning-the black bar safety net

At this year's Pwn2Own 2018 game, there is more for the Apple Safari browser attack challenge, today we will introduce for Safari remote code executionRCE, sandbox escapes, local privilege escalationLPEand for macOS 10.13.3 kernel exploits. To attack the challenges of the environment settings...

Safari Proxy Object Type Confusion

This module exploits a type confusion bug in the Javascript Proxy object in WebKit. The DFG JIT does not take into account that, through the use of a Proxy, it is possible to run arbitrary JS code during the execution of a CreateThis operation. This makes it possible to change the structure of e....

(Pwn2Own) Apple Safari DFG JIT Type Confusion Remote Code Execution Vulnerability

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of the...