3COM TFTPD Overflow: SEH Overwrite

[email protected] 25 Jan 2008 14:58:43 -0000
Newsgroups gmane.comp.security.vulnerabilities
Message-ID <[email protected]>
I'm attempting to exploit an already known bug in 3COM TFTPD server, and =
execute "calc.exe" with my shellcode.  I have control of ECX/EIP, and can=
 overwrite both SEH and pointer to next SEH successfully, and have used:=0D
=0D
Pointer to next SEH: \xeb\x10\x90\x90=0D
SEH: \x69\x12\xab\x71 (POP/POP/RET in  ws2_32.dll)=0D
=0D
A full writeup with screenshots is available at:=0D
http://filebin.ca/pmuwqm/SEHOverwrite.rtf=0D
=0D
I'm getting "Debugged program was unable to process exception", so I hit =
shift+f9 (in olly) and it terminates with some strange exit code.  Could =
you take a peek and see what I'm missing here?=0D
=0D
Thanks guys!=0D
=0D
-jj