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Executable installers are vulnerable^WEVIL (case 30): clamwin-0.99-setup.exe allows arbitrary (remote) code execution WITH escalation of privilege

Hi @ll,

the executable installer clamwin-0.99-setup.exe (available from
<http://www.clamwin.com/download>) loads and executes DWMAPI.dll
or UXTheme.dll from its "application directory".

For software downloaded with a web browser the application
directory is typically the user's "Downloads" directory: see
and <http://seclists.org/fulldisclosure/2012/Aug/134> for
"prior art" about this well-known and well-documented vulnerability.

If an attacker places one of the above named DLL in the user's
"Downloads" directory (for example per "drive-by download"
or "social engineering") this vulnerability becomes a remote
code execution.

Proof of concept/demonstration:

1. visit <http://home.arcor.de/skanthak/sentinel.html>, download
   <http://home.arcor.de/skanthak/download/SENTINEL.DLL>, save it
   as UXTheme.dll in your "Downloads" directory, then copy it as

2. download clamwin-0.99-setup.exe and save it in your "Downloads"

3. execute clamwin-0.99-setup.exe from your "Downloads" directory;

4. notice the message boxes displayed from the DLLs placed in
   step 1.


See <http://seclists.org/fulldisclosure/2015/Nov/101>,
<http://seclists.org/fulldisclosure/2015/Dec/86> and
<http://seclists.org/fulldisclosure/2015/Dec/32> plus
<http://home.arcor.de/skanthak/!execute.html> and
<http://home.arcor.de/skanthak/sentinel.html> for details about
this well-known and well-documented BEGINNER'S error!  

stay tuned
Stefan Kanthak

PS: I really LOVE (security) software with such trivial beginner's
    errors. It's a tell-tale sign to stay away from this snakeoil!


2016-03-06    sent vulnerability report to authors

<security@xxxxxxxxxxx>: host aspmx.l.google.com[] said: 550-5.1.1
    The email account that you tried to reach does not exist. Please try
    550-5.1.1 double-checking the recipient's email address for typos or
    550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1
    https://support.google.com/mail/answer/6596 y186si9894139wmy.43 - gsmtp (in
    reply to RCPT TO command)

<clamwin@xxxxxx>: host mx.sourceforge.net[] said: 550 unknown user
    (in reply to RCPT TO command)

2016-03-06    report published