Taltech Tal Bar Code ActiveX Control Memory Corruption
Michal Bucko (sapheal)
The Bar Code ActiveX Control has all the features necessary to easily add
professional quality barcodes to any Windows application including Web
database reporting and labeling, product packaging, document tracking,
bar coding and special purpose bar code labeling applications.
It is an extremely easy and powerful tool that will work flawlessly with
Windows application that supports ActiveX technology including Visual
C++, Internet Explorer Web pages, Microsoft Word, Excel, Access, etc.
The vulnerability lies in SaveBarCode function. The vulnerability allows
arbitrary code execution (in the context of current user) via a web
The debug snippet shows what happened to the default exception handler:
41414141 Pointer to next SEH record
41414141 SE Handler
Return address and default exception handler were overwritten.
The other interesting vulnerability (but much of a different character,
though) allows storage of files on the remote machine. The files contain
bar codes, however, such an issue might be exploited to store thousands of
files on the remote machine. The sample exploit for the second
is very simple and looks the following way (windows script file [wsf]):