What bug existed in the public Metasploit exploit script for CVE-2017-8464 and how was it fixed?

The original Metasploit script caused the `explorer.exe` process to crash after successfully executing the payload (e.g., calc.exe). The bug was traced to the DLL file generated by the exploit. The fix involved replacing the default DLL with a different one—either a 32-bit or 64-bit DLL from a tested open-source project—which stopped the crash and allowed “perfect exploitation.” For more details on the debugging process and the exact DLLs used, see the [Exploitation Testing of Windows Lnk Remote Code Execution Vulnerability (CVE-2017-8464)](/news/exploitation-testing-of-windows-lnk-remote-code-execution-vulnerability-cve-2017-8464) article.