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Author Topic: WebShield scans file types I have excluded  (Read 4442 times)

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Offline Lars-Erik

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WebShield scans file types I have excluded
« on: January 14, 2008, 04:15:30 AM »
1) I have exceptions for "IMAGE/GIF", "IMAGE/PNG" and "IMAGE/JPG"
2) I turn on the "Show detailed information"
3) I shows that ALL images of these types on web-pages are still scanned

Why?  Since the WebShield slows down quite a bit (earlier discussion) I don't want it to scan images, but only other content (like HTML-code, applets, executables etc). But the exclusions don't seem to work :-(
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Offline lukor

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Re: WebShield scans file types I have excluded
« Reply #1 on: January 14, 2008, 11:31:10 AM »
Lars-Erik,
webshield compares the content-type with the information sent by the server. It is possible, that the information sent about the image is somewhat different than you think. For example jpeg files are most probably described as : image/jpeg. I'm sure you have some pages with image/jpg as well, but you should try to add this string to the exclusion list.

Lukas.
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Offline Lars-Erik

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Re: WebShield scans file types I have excluded
« Reply #2 on: January 14, 2008, 12:26:26 PM »
I tried adding the "'*.jpg" to the URL exception list, and that works quite good, except when the image is not a static file, but a result of a script or something (then it doesn't end with "jpg"). I'll try your suggestion and see.
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Offline Lars-Erik

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Re: WebShield scans file types I have excluded
« Reply #3 on: January 14, 2008, 12:49:43 PM »
Didn't help adding IMAGE/JPEG :-(
Still had to add "*.jpg" and I guess that is not that safe (script etc could call them self .jpg right).
Does the case have anything to say (IMAGE/JPG vs image/jpg)?
Any other reason it does not work (I use Firefox)?
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Offline lukor

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Re: WebShield scans file types I have excluded
« Reply #4 on: January 15, 2008, 03:15:58 PM »
Lars-Erik, please post here the image URL and I'll tell you what is its content-type. Lukas
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Offline Lars-Erik

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Re: WebShield scans file types I have excluded
« Reply #5 on: January 15, 2008, 03:19:12 PM »
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Offline lukor

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Re: WebShield scans file types I have excluded
« Reply #6 on: January 15, 2008, 04:00:38 PM »
Hello Lars-Erik,

I've checked: http://www.vg.no/nyheter/

Most of the images on this page have content-type of "image/jpeg", some of them are gifs, so they have "image/gif". I have not seen any "image/jpg".

You might also see in the yellow WebShield bar (if show detailed info is on) listed some URLs with .jpg extension. I have analyzed those, and these are not JPG images! Have you checked that the urls your are reporting are indeed images?

An example can be this document:

Quote
URL: http://www.vg.no/nyheter/uploaded/image/bilderigg/2008/01/15/1200385682690_267.jpg
Content-type: text/html; charset=iso-8859-1

Contents:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://www1.vg.no/uploaded/image/bilderigg/2008/01/15/1200385682690_267.jpg">here</a>.</p>
<hr>
<address>Apache/2.0.52 (CentOS) Server at www.vg.no Port 80</address>
</body></html>


To sum up, I have tested WebShield in the latest version and I have not found a single issue where Content-Type exclusions are not working.

Cheers.
Lukas
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Offline Lars-Erik

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Re: WebShield scans file types I have excluded
« Reply #7 on: January 15, 2008, 04:18:08 PM »
What kind of files are those "*.jpg" files then?
Why would a serious newspaper use JPG on non-jpg files?
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Offline lukor

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Re: WebShield scans file types I have excluded
« Reply #8 on: January 15, 2008, 05:01:59 PM »
I have just posted the contents of the file together with its content type. It is a HTML document redirecting you to the actual location.
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