Windows 95/98,Windows NT Enterprise Server 4.0 SP1/SP2/SP3/SP4/SP5/SP6,Windows NT Server 4.0 SP1/SP2/SP3/SP4/SP5/SP6/SP6a,Windows NT Terminal Server 4.0 SP1/SP2/SP3/SP4/SP5/SP6,Windows NT Workstation 4.0 SP1/SP2/SP3/SP4/SP5/SP6/SP6a Riched Buffer Overflow Vulnerability
Riched20.dll and Riched32.dll, which Windows uses to parse Rich Text Forrmat files, have an unchecked buffer which allows arbitrary code to be executed. The code can be put into an .rtf file and emailed to the victim. Then if the victim opens the document, the code will be run at the same privilege level as the user.
NOTE: It has been reported on the Bugtraq mailing list that the patch provided by Microsoft does not completely fix the problem. A .rtf file with 1000 characters (instead of the original 32) will still crash the application reading the .rtf file.
This will crash Wordpad:
Create an .rtf file, then open it in notepad. The first line will look something like this:
Now insert 32 characters after the .rtf identifier:
When this file is opened in Wordpad, the program will crash.