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Re: Eudora executes (Java) URL

From: hightide () GINCH ORG (High Tide)
Date: Wed, 12 Aug 1998 10:29:08 -0500


Actually, I believe the RE that you are looking for is this:
s/<\s*BODY\s+((([^">]+("(\\.|[^"])*")?)*)ONLOAD)*?\s*/<BODY $1
DEFANGED-ONLOAD/gi;


Actually, I believe this discussion should be taken off bugtraq unless
someone knows how to fix the backtracking problem that I don't think even
made it to the list.

The problem is with the second (in the above expression) +, and the third
*.  What happens is as the regex is processing <BODY 123> it ends up
trying to find a match in with the following values for the [^">]+ :
123
12 3
1 23
1 2 3

I don't know if that makes any sense to you, but it's a exponential load
result, 2^(n-1) where n = len($x).  Try this regex on
<BODY $x>
for large values of len($x).

Sean Bastille
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