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What happens when you upload files to a non-system drive?
Attackers may attempt to: Execute denial of service attacks. Upload viruses or malware. Compromise networks and servers in other ways. Security steps that reduce the likelihood of a successful attack are: Upload files to a dedicated file upload area, preferably to a non-system drive.
Which is faster a database or a file upload?
For small file uploads, a database is often faster than physical storage (file system or network share) options. A database is often more convenient than physical storage options because retrieval of a database record for user data can concurrently supply the file content (for example, an avatar image).
Is there a limit to the number of files that can be upload?
For another example that loops over multiple files for upload and uses safe file names, see Pages/BufferedMultipleFileUploadPhysical.cshtml.cs in the sample app. Path.GetTempFileName throws an IOException if more than 65,535 files are created without deleting previous temporary files. The limit of 65,535 files is a per-server limit.
How does upload large files with streaming improve performance?
The file is received from a multipart request and directly processed or saved by the app. Streaming doesn’t improve performance significantly. Streaming reduces the demands for memory or disk space when uploading files. Streaming large files is covered in the Upload large files with streaming section.
Why are file uploads a risk to an application?
Uploaded files represent a significant risk to applications. The first step in many attacks is to get some code to the system to be attacked. Then the attack only needs to find a way to get the code executed. Using a file upload helps the attacker accomplish the first step.
What happens when you upload a malicious file?
Client-side attacks: Uploading malicious files can make the website vulnerable to client-side attacks such as XSS or Cross-site Content Hijacking. Uploaded files can be abused to exploit other vulnerable sections of an application when a file on the same or a trusted server is needed (can again lead to client-side or server-side attacks)
How is a file upload vulnerability detected by an attacker?
In the video demonstration below we show how a file upload vulnerability is detected by an attacker on a vulnerable website. The attacker then uses Metasploit to get a remote shell on the website. We show the capabilities that a remote shell provides an attacker.
Why are my files not uploading in ASP.NET Core?
If your controller is accepting uploaded files using IFormFile but you find that the value is always null, confirm that your HTML form is specifying an enctype value of multipart/form-data. If this attribute isn’t set on the element, the file upload won’t occur and any bound IFormFile arguments will be null.
How to upload a file to a folder?
PUT /me/drive/root:/FolderA/FileB.txt:/content Content-Type: text/plain The contents of the file goes here. If successful, this method returns an driveItem resource in the response body for the newly created file.