--Saturday, October 6, 2007, 9:06:51 PM, you wrote to bugtraq (at) securityfocus (dot) com [email concealed]:
TZ> Dear Geo.,
G>> If the application is what exposes the URI handling routine to untrusted
G>> code from the internet,
TZ> Sorry, Untrusted code from the internet ?
TZ> The user clicks on a mailto link, is that untrusted code?
TZ> Or the mailto link is clicked for him.
What URL is is defined by RFC 1738, what mailto: is is defined by RFC
2368. String in question is definetly _not_ URL because of %xx and ".
Double quote is URL delimiter and is not a part of URL, in this case
application incorrectly parses and highlights URL (it should stop before
"). %xx is invalid character encoding. And altogether it's, for sure,
not mailto: URL. Passing unchecked user input to function called
ShellExecute(), where URL is expected, is a bug.
So, while there is a security vulnerability in Windows, there is also
security vulnerability in mIRC, Acrobat Reader, Netscape, Miranda,
Skype, because ShellExecute() behaviour is not defined for the case
non-URL data is passed to URL processor.
--Saturday, October 6, 2007, 9:06:51 PM, you wrote to bugtraq (at) securityfocus (dot) com [email concealed]:
TZ> Dear Geo.,
G>> If the application is what exposes the URI handling routine to untrusted
G>> code from the internet,
TZ> Sorry, Untrusted code from the internet ?
TZ> The user clicks on a mailto link, is that untrusted code?
TZ> Or the mailto link is clicked for him.
What URL is is defined by RFC 1738, what mailto: is is defined by RFC
2368. String in question is definetly _not_ URL because of %xx and ".
Double quote is URL delimiter and is not a part of URL, in this case
application incorrectly parses and highlights URL (it should stop before
"). %xx is invalid character encoding. And altogether it's, for sure,
not mailto: URL. Passing unchecked user input to function called
ShellExecute(), where URL is expected, is a bug.
So, while there is a security vulnerability in Windows, there is also
security vulnerability in mIRC, Acrobat Reader, Netscape, Miranda,
Skype, because ShellExecute() behaviour is not defined for the case
non-URL data is passed to URL processor.
--
~/ZARAZA http://securityvulns.com/
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