Bug #75840 [Opn->Fbk]: when i load COM('WScript.shell') and call exec('cmd.exe /c whoami') to execute

Edit report at https://bugs.php.net/bug.php?id=75840&edit=1 ID: 75840 Updated by: ab@php.net Reported by: zhang_xiaobao at venustech dot com dot cn Summary: when i load COM('WScript.shell') and call exec('cmd.exe /c whoami') to execute -Status: Open +Status: Feedback Type: Bug Package: COM related Operating System: windows PHP Version: 7.0.27 Block user comment: N Private report: N New Comment: Thanks for sending the crash dump. Unfortunately i could only see a few stack frames, because the libhttpd.dll is missing the debug symbols and they're not provided by XAMPP, too. Eg. > libhttpd.dll!_ap_run_generate_log_id@12() + 7350 bytes Unknown No symbols loaded. [Frames below may be incorrect and/or missing, no symbols loaded for libhttpd.dll] Annotated Frame libhttpd.dll!_ap_signal_parent@4() + 7799 bytes Unknown No symbols loaded. libhttpd.dll!_ap_run_mpm@12() + 43 bytes Unknown No symbols loaded. httpd.exe!OPENSSL_Applink() + 2950 bytes Unknown No symbols loaded. Please also note, that the lack of debug symbols is a usual thing, if no official builds are used. From the code flow, the command execution would normally block until the command has finished. Every thread has it's own structures, that would be destroyed separately. However one guess that i have is about OpenSSL. The report is about 7.0.27 which we officially link with OpenSSL 1.0.2, but from the dump i see that the Apache distribution is linked with OpenSSL 1.1.0. It is likely to cause issues in completely unrelated parts. So please check and ensure, that both PHP and Apache are linked with the same OpenSSL version. It were preferable to use teh official PHP builds and httpd from apachelounge.com. Please also ensule that the runtime is same, too. Another point is - PHP below 7.2 has issues with the thread safety, which was fixed in 7.2 and won't be backported. It might make sense, now that 7.2 is out and you use PHP as Apache module, to upgrade it. On my side, i've also tested your snippet with PHP as Apache module under quite some stress scenarios like "ab -c 4", but still couldn't able to get on the crash :( Thanks. Previous Comments: ------------------------------------------------------------------------ [2018-01-22 05:46:53] zhang_xiaobao at venustech dot com dot cn I hava already sent the process dump information to you by email(1486805345@qq.com),please check it. ------------------------------------------------------------------------ [2018-01-22 05:31:35] zhang_xiaobao at venustech dot com dot cn Because of the work mailbox has an attachment size limit,I will send process dump information for you through my other mailbox(1486805345@qq.com). ------------------------------------------------------------------------ [2018-01-20 19:29:38] ab@php.net Thanks for the report. I currently don't reproduce any crash with your code. Could you please provide a corresponding backtrace and/or crash dump? Modules are only freed at the process exit, mpm_winnt is only one child per server. Is that about mpm_winnt or fcgi? Disregarding the possible crash, I'd not see this as a security issue. Thanks. ------------------------------------------------------------------------ [2018-01-18 09:10:56] zhang_xiaobao at venustech dot com dot cn Description: ------------ <?php $wsh = new COM('WScript.shell'); $exec = $wsh->exec('cmd.exe /c whoami'); $stdout = $exec->StdOut(); $stroutput = $stdout->ReadAll(); echo $stroutput; ?> Test script: --------------- <?php $wsh = new COM('WScript.shell'); $exec = $wsh->exec('cmd.exe /c whoami'); $stdout = $exec->StdOut(); $stroutput = $stdout->ReadAll(); echo $stroutput; ?> Expected result: ---------------- 1. First of all, add extension=php_com_dotnet.dll in php.ini. 2. when i load COM('WScript.shell') and call exec('cmd.exe /c whoami') to execute system command,the inside of the com waits for the process to exit, as the same time,the com is freed by other modules,when the cmd.exe exited, the thread who suspend with the waitformultipleobjects function is activated. but the eip is not invalid,because of the memory is free. Actual result: -------------- It cause the process of httpd.exe to crash. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75840&edit=1