Linked Questions
15 questions linked to/from Is it safe to serve any user uploaded file under only white-listed MIME content types?
3
votes
6
answers
28k
views
Use PHP to check uploaded image file for malware?
I want my users to be able to upload a photo. Currently I am not checking the uploaded photo for problems of any kind, although I do limit the size to 32k.
Is there any way for me to check uploaded ...
- 113
46
votes
5
answers
86k
views
How to scan a PDF for malware? [closed]
Can anyone suggest an automated tool to scan a PDF file to determine whether it might contain malware or other "bad stuff"? Or, alternatively, assigns a risk level to the PDF?
I would prefer a free ...
- 99.6k
8
votes
5
answers
2k
views
How should I serve untrusted / unsanitized documents (PDF, DOC, XLS) to end users over the web?
My website will be hosting documents for end users and I would like to make this as secure as possible.
Question
Assuming that I have a need to share documents on a website that may contain hostile ...
- 50.9k
20
votes
4
answers
3k
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 ...
- 1,932
11
votes
4
answers
3k
views
Preventing insecure webapp on subdomain compromise security of main webapp
I want your help on getting more concrete information on a type of vulnerability that I remember vaguely.
I vaguely remember hearing about a year ago that if you set up a webapp on a subdomain, and ...
- 2,058
2
votes
4
answers
3k
views
Security risks of hosting user-supplied images?
I have a program that will accept and fetch images from urls. It will check if the extension is .png, .jpg, etc...
I will fetch these files and store them, they will be shown to users in a gallery (...
- 54.4k
20
votes
3
answers
23k
views
Does X-Content-Type-Options really prevent content sniffing attacks?
In Tangled Web Michal Zalewski says:
Refrain from using Content-Type: application/octet-stream and use application/binary instead, especially for unknown document types. Refrain from returning ...
- 5,397
17
votes
3
answers
8k
views
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 ...
- 1,087
14
votes
3
answers
26k
views
Is it possible to inject HTML into image to provoke XSS?
Some answers mention that it's possible to inject attacker-controlled HTML into images and therefore provoke XSS.
I guess that this HTML will be processed by browser only if hole exists in browser. ...
- 5,397
10
votes
3
answers
7k
views
Security/Malware implications of storing data in a BLOB as opposed to the file system
From a programming perspective, there has long been a debate over whether to store files in a BLOB or Binary field in a database, or on the file system. The debate always seems to center around ...
- 2,686
8
votes
3
answers
3k
views
How to safely allow upload of executable files [duplicate]
I need help regarding file uploading. In one of my projects the client wants to allow a file upload without restrictions on the file type. But I'm afraid that then users can upload executable files ...
- 89
4
votes
3
answers
2k
views
Flash ignores Content-Type header, allowing XSS?
I recently read that the Flash plugin ignores the Content-Type header in certain circumstances. In particular, you can give Flash a URL, and the Flash plugin will happily fetch the content at that ...
- 99.6k
1
vote
2
answers
618
views
Malware prevention of data received in a POST endpoint
Problem
Having one HTTPS api which has an endpoint i.e POST data how can we prevent/check that the data received is not malicious or possibly detrimental?
To consider (please read)
POST data receives ...
- 65
3
votes
1
answer
3k
views
Unrestricted File upload [closed]
I am working on a file upload feature in our app. Users can also download uploaded files from the app. To prevent malicious file upload, I am checking magic bytes of the file to find the file type ...
- 261
2
votes
1
answer
653
views
How confident is MIME blacklisting on a proxy server?
We are blacklisting a number of MIME types on our proxy server so users can't download certain file types, for example, executables.
Could it be possible that somehow, a malicious server can trick a ...
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