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"Strip Script Tags" in FW-1 can be circumvented


From: arne.vidstrom () NTSECURITY NU (Arne Vidstrom)
Date: Sat, 29 Jan 2000 14:51:46 +0100


Hi all,

The "Strip Script Tags" in FW-1 can be circumvented by adding an extra <
before the <SCRIPT> tag like in this code:

<HTML>
<HEAD>
<<SCRIPT LANGUAGE="JavaScript">
alert("hello world")
</SCRIPT>
</HEAD>
<BODY>
test
</BODY>
</HTML>

This code will pass unchanged, and still execute in both Navigator and
Explorer. I tried this on version 3.0 of FW-1 (on Windows NT 4.0) but I'm
not able to check it on version 4.0 since I don't have access to it.

/Arne Vidstrom

http://ntsecurity.nu


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