BID:10344

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

Info

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

Bugtraq ID:	10344
Class:	Access Validation Error
CVE:
Remote:	Yes
Local:	No
Published:	Nov 25 2003 12:00AM
Updated:	Nov 25 2003 12:00AM
Credit:	Discovery is credited to Liu Die Yu, Grey Magic and The Pull.
Vulnerable:	Microsoft Internet Explorer 6.0 SP1 Microsoft Internet Explorer 6.0 - Microsoft Windows 2000 Advanced Server SP2 - Microsoft Windows 2000 Advanced Server SP2 - Microsoft Windows 2000 Advanced Server SP2 - Microsoft Windows 2000 Advanced Server SP1 - Microsoft Windows 2000 Advanced Server SP1 - Microsoft Windows 2000 Advanced Server SP1 - Microsoft Windows 2000 Advanced Server - Microsoft Windows 2000 Advanced Server - Microsoft Windows 2000 Advanced Server - Microsoft Windows 2000 Datacenter Server SP2 - Microsoft Windows 2000 Datacenter Server SP2 - Microsoft Windows 2000 Datacenter Server SP2 - Microsoft Windows 2000 Datacenter Server SP1 - Microsoft Windows 2000 Datacenter Server SP1 - Microsoft Windows 2000 Datacenter Server SP1 - Microsoft Windows 2000 Datacenter Server - Microsoft Windows 2000 Datacenter Server - Microsoft Windows 2000 Datacenter Server - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional - Microsoft Windows 2000 Professional - Microsoft Windows 2000 Professional - Microsoft Windows 2000 Server SP2 - Microsoft Windows 2000 Server SP2 - Microsoft Windows 2000 Server SP2 - Microsoft Windows 2000 Server SP1 - Microsoft Windows 2000 Server SP1 - Microsoft Windows 2000 Server SP1 - Microsoft Windows 2000 Server - Microsoft Windows 2000 Server - Microsoft Windows 2000 Server - Microsoft Windows 2000 Terminal Services SP2 - Microsoft Windows 2000 Terminal Services SP2 - Microsoft Windows 2000 Terminal Services SP2 - Microsoft Windows 2000 Terminal Services SP1 - Microsoft Windows 2000 Terminal Services SP1 - Microsoft Windows 2000 Terminal Services SP1 - Microsoft Windows 2000 Terminal Services - Microsoft Windows 2000 Terminal Services - Microsoft Windows 2000 Terminal Services - Microsoft Windows 98 - Microsoft Windows 98 - Microsoft Windows 98 - Microsoft Windows 98SE - Microsoft Windows 98SE - Microsoft Windows 98SE - Microsoft Windows ME - Microsoft Windows ME - Microsoft Windows ME - Microsoft Windows NT 4.0 SP6a - Microsoft Windows NT 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Terminal Server 4.0 SP6a - Microsoft Windows NT Terminal Server 4.0 SP6a - Microsoft Windows NT Workstation 4.0 SP6a - Microsoft Windows NT Workstation 4.0 SP6a - Microsoft Windows NT Workstation 4.0 SP6a + Microsoft Windows Server 2003 Datacenter Edition + Microsoft Windows Server 2003 Datacenter Edition + Microsoft Windows Server 2003 Datacenter Edition + Microsoft Windows Server 2003 Datacenter Edition Itanium 0 + Microsoft Windows Server 2003 Datacenter Edition Itanium 0 + Microsoft Windows Server 2003 Enterprise Edition + Microsoft Windows Server 2003 Enterprise Edition + Microsoft Windows Server 2003 Enterprise Edition + Microsoft Windows Server 2003 Enterprise Edition Itanium 0 + Microsoft Windows Server 2003 Enterprise Edition Itanium 0 + Microsoft Windows Server 2003 Enterprise Edition Itanium 0 + Microsoft Windows Server 2003 Standard Edition + Microsoft Windows Server 2003 Standard Edition + Microsoft Windows Server 2003 Standard Edition + Microsoft Windows Server 2003 Web Edition + Microsoft Windows Server 2003 Web Edition + Microsoft Windows Server 2003 Web Edition + Microsoft Windows XP Home + Microsoft Windows XP Home + Microsoft Windows XP Home + Microsoft Windows XP Professional + Microsoft Windows XP Professional + Microsoft Windows XP Professional

Not Vulnerable:

Discussion

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

A vulnerability has been reported that may potentially permit HTML documents to gain unauthorized access to local resources by using specific syntax when referencing said resource as a value for the CODEBASE object property. Under certain conditions, this could be exploited to reference executable content on the victim system.

In particular, by pre-pending two backslash characters (\\) to the resource path, it may be possible to invoke the resource. This syntax is reportedly still valid despite patches to limit other means of allowing remote users to reference local content on client systems.

This works if the resource is invoked from the Local Zone, so other vulnerabilities are required to bypass Zone restrictions and cause malicious content to be executed in the Local Zone. BIDs 9658, 9320, 9105, and 9107 could all theoretically be exploited in combination with this issue, potentially allowing for execution of arbitrary code on the client system if properly exploited.

Attacks that exploit this issue in tandem with other vulnerabilities may be executed through Internet Explorer or HTML email via Outlook/Outlook Express.

Note: This BID initially included a proof-of-concept that was published by Roozbeh Afrasiabi that caused a .CHM file to be referenced from the Internet Zone. Further research has determined that this is a new, distinct vulnerability and BID 10348 has been created to describe this issue.

Exploit / POC

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

The following proof-of-concepts were provided by Liu Die Yu:

file://[SysDrive]:\\[INTERNET CACHE PATH]\CONTENT.IE5\EXE.EXE

mhtml:file://[SysDrive]:\\[INTERNET CACHE PATH]\CONTENT.IE5\MHT.MHT!file:///C:\EXE.EXE

Solution / Fix

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

Solution:
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.

References

Microsoft Internet Explorer Codebase Double Backslash Local Zone File Execution Weakness

References:

Unpatched Internet Explorer Bugs (Liu Die Yu)