File upload means sending a file from a local system to a remote system such as a server or another client with the intent that the remote system should store a copy of the file being transferred.

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Exploits or other security risks with SVG upload?

I have a site, where people can upload graphics, you might think of it like an image hoster or a forum for pictures. Now, I allow upload of raster graphics to a certain size, but no vector graphics ...
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1answer
188 views

users avatar names based on Primary Key, is it safe?

We upload users avatar with their primary key name. avatars name are 1.jpg,2.jpg,3.jpg,... according to their primary key. We implemented this to omit avatar field from database, instead with use ...
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3answers
405 views

Is changing image's extension prone to error for browsers?

In my uploading user's avatar scenario, I change users picture extension to jpg. Is this making the browsers to act differently? Is it prone to error for browsers when they read users avatar? ...
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2answers
1k views

Antivirus for scanning anonymous file uploads

Since I have no experience with AV solutions on Unix-like environments, I would need help with suggestions on something that can be suitable for scanning files that are uploaded by anonymous users ...
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4answers
590 views

Is it safe to store and replay user-provided mime types?

If a user uploads a file but modifies the request by setting the mime-type to something arbitrary, like "superdangerous/blackhatstuff", is it safe for me to send the same mime type back to a different ...
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5answers
167 views

Should there be an anti-virus used on client provided files?

This is based on Stack Exchange podcast # 25. I really don't understand why there would need to be virus checking on uploaded files. It would generally be a bad idea to execute anything which was ...
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3answers
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How can I be protected from pictures vulnerabilities?

I've just read this question What is the corrupted image vulnerability? How does it work? (GIFAR, EXIF data with javascript, etc..) I'm asking myself how can I protect myself and my website's users. ...
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3answers
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Using file extension and MIME type (as output by file -i -b) combination to determine unsafe files?

We allow users to upload a number of files, all of which we either send over to scribd (doc, xls, ppts, etc) or display as a video ourselves (flv, mov, mp4, etc in flowplayer). To avoid users ...
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6answers
929 views

How to defend vs. Image Remote File Inclusion, e.g. RFI using a .gif file (Apache/PHP)?

To defend versus Remote File Inclusion where attackers try to abuse image files, I usually recommend to never use include to include image files into PHP code. Sometimes though, the avoidance of ...
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3answers
2k views

What are the security risks of letting the users upload content to my site?

As a web designer (not a security expert) I wonder: If I allow users to upload content to my website (videos, images and text files), what are the real risks involved?
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3answers
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What steps should be taken to validate user uploaded images within an application?

Recently I have worked on a number of applications that need to process user uploaded images steps have been taken to validate the extension and the mime type. But what else can be done to ensure ...