Microsoft Windows Live Messenger Live Call Local Privilege Escalation Vulnerability

["David Maciejak" <david.maciejak () gmail com>]

Hi,

Playing around with privilege escalation I found that WLM 8.0, 8.1 and
probably newer (since live call feature in fact) are vulnerable to a local
privilege escalation issue. It's not a critical flaw.
The problem occurs when livecall.exe process is launch.
The first time, the user need to click on phone icon after that each time
it connect back on WLM the livecall.exe process is autolaunch.
Quotes must be missing when this process is launch through svchost.exe
because it tries first to launch Program.exe file at root default windows drive.
Then, to exploit this issue the malicious user need to have enough write
permission on default root path and wait for a more privilege user to
connect to the local WLM.

I have contacted Microsoft Security Team about that on July 11 2007,
for them "this does not appear to be a security vulnerability". I
don't think a patch will be addressed soon.

cheers,
David Maciejak

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