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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3
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0answers
94 views

Is there a way my organization can collect clients' sensitive documents without being liable for them? [closed]

I am the head of IT for a microlending organization. We make small loans to new businesses, and as such we have to collect these clients' tax returns and other financial data as part of the ...
2
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1answer
61 views

Arbitrary file upload, serve JPG as PHP

I'm trying out random older WordPress exploits on my local server, I'm currently in the process trying to get this one to work: https://www.exploit-db.com/exploits/20083/ It doesn't read any ...
0
votes
0answers
49 views

Bypassing Change Name Uploader

I have read all of the questions available on SE about bypassing the change name uploader. Consider an uploader which changes the file name each time you try to upload a file. The only allowed formats ...
0
votes
2answers
81 views

Getting the uploaded file path without knowing the uploading destination

Imagine a scenario that we are able to upload a PHP file on the server. However, we are not aware of the uploading path. I simply mean that, we are able to upload the file but we don't know where it ...
2
votes
0answers
43 views

Simple method requiring no installation of special tools to share a file over the internet

I have searched for related topics, but found other existing answers to not be satisfactory, because they require installing special tools. This is a very common use case. For example, I want to ...
2
votes
1answer
99 views

Prevent shell script inside image file

Recently, one of my website was hacked by someone who uploaded an image (shell.gif) to my server. I have put server side validation to check file extension + mime type of the image. However, they are ...
1
vote
2answers
49 views

So I need to unzip and process user submitted zip files - how to do so securely?

I am writing a system that accepts zipfiles from end users. The title says it all - what precautions should I take to ensure my processing server does not get compromised when I need to unzip a ...
1
vote
2answers
119 views

Will a crossdomain.xml file reduce a potential security risk?

I maintain a website were users are allowed to upload files. I'm doing already some good MIME-checks, consistency checks, virus checks, blacklist checks based on hash lists, some other custom checks ...
1
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0answers
135 views

Deobfuscated Malicious PHP Code Comprehensively [closed]

I found 3 php files in a htaccess-password-protected upload folder on my server: 1. default_folders.php 2. factory.php 3. HMAC.php Each of them contains a variable string, eg: ...
2
votes
1answer
105 views

Server side validations for file upload to prevent DoS on HTTP server

I am aware that client side validations can be easily bypassed by means like disabling javascript. I would like to know the things to be checked while doing a server side validation for file upload. I ...
1
vote
0answers
33 views

Unrestricted file upload on a cloud based platform [closed]

We have an unsecured file upload for the user to upload any file they want, our application is Azure based so they are stored as blobs not as a traditional "file on disk". Could malicious code still ...
4
votes
3answers
220 views

PHP | Security for allowing user uploads

My Sittuation: I am creating a web application with PHP which allows users to scan their files for viruses. It allows the user to upload their files via the html "file" input type or via a URL. I ...
4
votes
5answers
229 views

Is it dangerous to serve user-uploaded Flash (SWF) files?

I'm working on a site that has CMS functionality. I'm considering allowing users to upload Flash (.swf) files and then displaying them on my site. Is this a bad idea? Is there a way to do this ...
1
vote
1answer
81 views

Secure (P2P) Client/Company File Sharing

my small web design company currently uses a cloud storage service to collaborate with our clients and I would like an easier (and more secure) way for files to be transferred-in and stored. The ...
1
vote
0answers
167 views

Run a uploaded file with a double extension? [closed]

I tested some pieces of code from an old project. I found something that looks like it could be an exploit, but I do not manage to exploit it completely. Here is the code: $target = "folder/"; ...
1
vote
1answer
504 views

Bypassing file upload restrictions

However an exercise I do not manage to resolve, I have to bypass a check of extension of a form in PHP. It turns out that just the extension is verified, but certain special characters are replaced ...
9
votes
1answer
114 views

Security measures and anti-virus on server to mitigate acting as a propagation vector

We have a web application for which I've been asked to add the ability to let users upload documents that will then be visible and downloadable by other users. Those documents will typically be images ...
2
votes
2answers
679 views

Is it possible to exploit a file upload with whitelist and filename hashing?

I have a small web application. Because it is necessary to upload some files I check the file extensions with a whitelist (tgz, jpg, png, pdf, zip, rar, txt, gif, py, c, rb). In addition to that, I ...
0
votes
1answer
71 views

How to protect user privacy when sharing photos?

I have a web site that lets users upload a profile picture that is then visible to other users of the site. What steps should the site take to protect user privacy? For example, some Jpeg files may ...
2
votes
1answer
139 views

Bypass Text Plain Rule

I want to know if I can allow uploading all types of scripts and add these rules to a virtual host configuration; so please advise and tell me if there will be some exploits that can be used to ...
2
votes
1answer
142 views

Where to store uploaded images from perspective of security

It is quite common that uploaded files (images, videos, etc.) are stored on a file server because of performance and database-recovery-time reasons. But is there a benefit of storing such files in ...
0
votes
2answers
137 views

How to transfer securely a file between servers?

Let's say I have two Linux servers. One containing a desktop app database (running on a local network) and a webserver. I want to automatically transfer each hour a database file (with a size of a ...
0
votes
2answers
168 views

Is there any reason to send file checksum for signed, encrypted files with MDC

I am using OpenPGP and sending a signed, encrypted file with forced MDC (Modification Detection Code) over the network. In typical file transfer scenarios where security is not in picture, an md5 ...
1
vote
2answers
203 views

Is php DOMDocument::loadXML completely secure?

Our application is using loadXML extensively to recieve data(input) from the users. Other than the usual checks for SQL injections and XXS, are there any known risks in parsing the xml file using ...
1
vote
1answer
143 views

What are the risks when processing a document with Apache POI?

Apache POI is a Java library for processing office documents. What are the risks associated with processing untrusted documents? For example, a web site that allows users to upload documents that are ...
0
votes
2answers
441 views

Encrypted offsite storage using sshfs and cryptsetup/dm-crypt/LUKS

I'm interested in an encrypted offsite storage scheme, but I don't want to depend on the vendor for encryption. I have an idea for doing so by combining sshfs with cryptsetup/dm-crypt/LUKS, but I'd ...
1
vote
0answers
67 views

Securing server from attacks and linking while allowing users to upload and store personal files?

I have read some questions and answers about uploading images specifically: Have I done enough not be compromised through image uploading Risks of a php image upload form Uploading images safe of ...
1
vote
1answer
75 views

Is it safe to put the output of 'strace' online?

For debugging purposes, one might be asked to put the output of strace for some process online, i.e. attached to a bug report. Is this safe in general? Under what circumstances is this safe or ...
1
vote
2answers
416 views

I can upload any file to an ASP webapp/IIS server but I do not know where (which folder), is this exploitable?

I'm able to upload any file to an ASP webapp/IIS server. My first though is to upload an ASP shell but I don't know where the file has been uploaded. I have written a Python script that beggining ...
-1
votes
1answer
254 views

BigDump v0.35b vulnerability [closed]

I dont understand what the problem with BigDump v0.35b. This site says that it have problem. But i dont understand it. Problem here? if (!$error && isset($_REQUEST["uploadbutton"])) { if ...
12
votes
5answers
4k views

Is there a way to check the filetype of a file uploaded using PHP?

I don't want it to just check the extension of the file as these can easily be forged even MIME types can be forged using tools like TamperData. So is there a better way to check file types in PHP ? ...
1
vote
5answers
408 views

How to ensure that files uploaded by users do not contain any Javascript

I'm trying to make a file uploader using PrimeFaces, but it is vulnerable to scripts: If someone tries to upload a file (e.g. a résumé) that includes JavaScript, this could get executed once the file ...
1
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1answer
36 views

make specially encoded template available for file uploads

A comment to this blog post at sans.org about secure file uploads suggests making a pre-formatted template available for users when they need to do file uploads. The user would use the template to ...
0
votes
1answer
145 views

Dangers of PHP uploading word docs into a quarantine

I plan to write a PHP script which will allow web users to upload MS Word formatted docs. Here are the precautions I am taking: Filenames will be created by me (something like YYYY-MM-DD.doc) Files ...
2
votes
1answer
649 views

One-Way Data Transfer Cable

Is there a cable that physically only supports data flow in one direction (out)? The idea here is to put this on a system that can only export data so that there is very minimal risk of the ...
4
votes
3answers
8k views

How does SFTP function without a manually generated public/private key pair

I am learning about SSH and how to use it to secure file transfers and commands between a windows machine and a Linux server. Everything that I have read so far indicates that I need to use an SFTP ...
1
vote
1answer
217 views

A renamed exe automatically running

We are currently developing a web app that allows users to upload files to act as attachments to information they provide. Obviously allowing users to upload any file types is very dangerous, ...
1
vote
1answer
292 views

Uploading Executable Files

Using proxy software, I was able to bypass a file upload control file-checking for an asp.net system I am pen testing. I noticed they are saving the file into the database as bytes, and it is ...
1
vote
0answers
2k views

blueimp jQuery-File-Upload getting PHP Hacked [closed]

I really like this upload package and want to use it, but from the time I set it up on my server, I've been hacked twice by something called the AnonGhost virus (anonghost.com). I tracked the ...
1
vote
1answer
1k views

File upload vulnerability

I am trying to pentest a webapp challenge. Is the following control code vulnerable to file upload? I would like to upload a php shell... I am able to upload shell.php.jpg file but I receive the ...
1
vote
1answer
342 views

Have I done enough not be compromised through image uploading

I know that you can never be sure that you have done enough to be secure, and I also know that file uploading is hard to make correct. Before asking this question I read some of the related posts here ...
2
votes
1answer
153 views

Can an inaccessible uploaded PDF harm a server?

Is it possible for an uploaded PDF file to harm an Apache server, if the filepath can't be found? That is, the PDF file can't be viewed from the browser or accessed by a known path once uploaded. I ...
1
vote
1answer
185 views

Uploading Disabled for executable file during change of Extension

As we know, uploading of executable file is not safe. But if we change extension of file exe to txt, then file get uploaded. How to prevent this??
0
votes
3answers
426 views

Secure uploading file

I have file uploaded system in my php project. What I make at uploading: 1) Check file extension and file mime type. 2) If extension and mime type are allowed types, I save file outside of ...
0
votes
3answers
166 views

Regarding Cross-Site Scripting attacks

My application has an Upload Management Module and accepts Excel and text files to our server. I detected invalid data inside some uploaded files (the uploader put ...
1
vote
2answers
131 views

Enforce a time limit on the number of uploads per user

I've done a lot of searching on SE and particularly here in regards to preventing issues or attacks for an image based website to accept image uploads, but I haven't seen anyone mention the idea of ...
2
votes
2answers
777 views

Unrestricted File Upload - Possible exploits

During a penetration test‎ (exercise) on a IIS web server + MYSQL DBMS, I have found an Unrestricted File Upload vulnerability for which I can upload a .php file. So I have tried to upload a php ...
3
votes
2answers
2k views

What does it mean to have a “file name with NULL bytes in serialized instances”?

I was browsing this page, which redirected me to this vulnerability because I'm a Java developer and I'm aware of the affected library. Basically the vulnerability says: It was discovered that ...
1
vote
1answer
1k views

Uploading JSP (Any kind of java code) to Tomcat without manager

I'm new to this site. I have a question concerning the upload of dynamic java code into an application running on Tomcat 7.0.34. I'm doing a penetration testing of a java website and found it's ...
0
votes
1answer
84 views

What's recommended for performance & security : Server as PC or Server as HDD [closed]

we are trying to find a file server for us. we look for the best practices of the establishment of an efficient and secure server. Therefore, my question is: What is recommended: server as a PC or ...