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Safari Proxy Object Type Confusion

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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.g. an argument without causing a bailout, leading to a type confusion (CVE-2018-4233). The JIT region is then replaced with shellcode which loads the second stage. The second stage exploits a logic error in libxpc, which uses command execution via the launchd's "spawn_via_launchd" API (CVE-2018-4404).


  • saelo




python, cmd


Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/osx/browser/safari_proxy_object_type_confusion
msf exploit(safari_proxy_object_type_confusion) > show targets
msf exploit(safari_proxy_object_type_confusion) > set TARGET < target-id >
msf exploit(safari_proxy_object_type_confusion) > show options
    ...show and set options...
msf exploit(safari_proxy_object_type_confusion) > exploit

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