File upload is becoming a more and more essential part of any application, where the user is able to upload their photo, their CV, or a video showcasing a project they are working on. The application should be able to fend off bogus and malicious files in a way to keep the application and the users safe.
In order to assess and know exactly what controls to implement, knowing what you're facing is essential to protect your assets. The following sections will hopefully showcase the risks accompanying the file upload functionality.
There is no silver bullet in validating user content. Implementing a defense in depth approach is key to make the upload process harder and more locked down to the needs and requirements for the service. Implementing multiple techniques is key and recommended, as no one technique is enough to secure the service.
The Content-Type for uploaded files is provided by the user, and as such cannot be trusted, as it is trivial to spoof. Although it should not be relied upon for security, it provides a quick check to prevent users from unintentionally uploading files with the incorrect type.
Some files are emailed or processed once they are uploaded, and are not stored on the server. It is essential to conduct the security measures discussed in this sheet before doing any actions on them.
The application should set proper size limits for the upload service in order to protect the file storage capacity. If the system is going to extract the files or process them, the file size limit should be considered after file decompression is conducted and by using secure methods to calculate zip files size. For more on this, see how to Safely extract files from ZipInputStream, Java's input stream to handle ZIP files.
Input Validation should not be used as the primary method of preventing XSS, SQL Injection and other attacks which are covered in respective cheat sheets but can significantly contribute to reducing their impact if implemented properly.
The upload feature should be using an allow-list approach to only allow specific file types and extensions. However, it is important to be aware of the following file types that, if allowed, could result in security vulnerabilities:
Dragging files to a folder in Drive for desktop automatically uploads them to Drive on the web (though it might take a moment for files to sync). When you see Upload complete, your files have uploaded successfully and can be accessed in any browser or device that has Drive installed.
The challenge this presents to social media marketers is that they need to keep their ears permanently to the ground, so to speak. The last thing anyone working in this space wants is to upload an image that gets stretched, cropped, resized, compressed, rejected, or altered in a way that makes their brand look like they JUST discovered the internet.
Since 2011, Dreamgrow has been keeping tabs on ol' Zuckerberg and his posse, tracking every pertinent change the guys and girls in Menlo Park have made to their platform, and logging wherever this affects the image and video sizes you can upload.
The ideal sizes for your profile image are 360360 pixels or 720720 pixels. These sizes are, respectively, double and quadruple the size of the minimum upload size. Some designers even recommend uploading at the maximum size of 2048 x 2048.
Facebook group cover photos are the largest images you can upload to any Facebook profile. This is great because you get to use as much real estate as possible to wow visitors into becoming group members.
Facebook recommends advertisers use stereo AAC compression at 128kbps on their uploads. Story video ads are perfect for audio, so feel free to infuse yours with a lush soundtrack or quality narration.
A predefined CSV template needs to be downloaded from the application and after providing all the details of spare parts in this CSV, the user uploads the same in the SAP AIN application. The spare parts details are stored in SAP AIN, after successful upload of the CSV.
The process would conceivably incorporate different steps, like mind copying, mind transfer, mind preservation, and whole brain emulation (WBE). Here is a detailed overview of how mind uploading can actually work:
However, mind uploading advocates claim that noninvasive brain scans can provide sufficient resolution for copying the brain without actually killing the person to do it. The information stored in our brain would then be used to create a connectome, a complete map of the neural connections in the brain, created using incredibly precise scanning of the neurons, and the synapses.
Brain-computer interfaces which would allow mind uploading would need a technology similar to modern-day brain scanning technology. Some suggest that downloading consciousness would require technology capable of scanning human brains at a quantum particle level.
Some wealthy individuals who wish to live forever are opting to preserve their brains and sometimes bodies through cryopreservation. In theory, in the future when human connectome technology is fully developed, their consciousness could then be retrieved and uploaded. An American cryonics company Alcor Life Extension Foundation already stores around 180 cryopreserved human bodies (with more preserving just their head) at its Phoenix-based facility.
One element of this process that may give some pause for thought, however, is that the "brain embalming" needs to take place while the person is still alive. The company hopes the process will be allowed as part of doctor-assisted suicide programs. Even if it does not lead to an uploading technology, any brains that Nectome manages to preserve might help in the research towards building the human connectome.
However, if the consciousness is uploaded as a substrate-independent mind (SIM), and if the SIM is deemed to be conscious, then it will also need to exist in a place and be able to interact with things. This will require virtual reality that is identical to how humans experience actual reality, everything from tasting a soda to feeling the pain of a car accident. All of this will require yet more storage capacity, signal bandwidth, and power.
Another study reveals, that depending on their personal views on death, suicide, fiction, philosophy, and science, some people may show great support for mind uploading, while others strongly disapprove of any such practice.
Sure, mind uploading has the potential to change human lives forever, but this is also why the advent of this sci-fi technology in the real world might also give rise to a lot of conflicts revolving around its ethical and social impact on humanity.
Steve Jobs once said, "Death is very likely the single best invention of Life. It is Life's change agent. It clears out the old to make way for the new." If this is true, then defeating death by mind uploading may in fact be self-defeating. It would allow a few individuals to go on, but at the expense of everything and everyone else.
For now, a number of scientists, researchers, and tech companies are working towards making mind uploading a reality. Whether they would be successful or not, and how our society would react to consciousness transfer, only the future could tell.
Uploaded files represent a significant risk to applications. The firststep 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. Usinga file upload helps the attacker accomplish the first step.
The consequences of unrestricted file upload can vary, includingcomplete system takeover, an overloaded file system or database,forwarding attacks to back-end systems, client-side attacks, or simpledefacement. It depends on what the application does with the uploadedfile and especially where it is stored.
Sometimes web applications intentionally or unintentionally use somefunctions (or APIs) to check the file types in order to process themfurther. For instance, when an application resize an image file, it mayjust show an error message when non-image files are uploaded withoutsaving them on the server.
When enumerating web applications, we often find ourselves in front of a file upload file that allows us to potentially upload malicious files onto the application, such as a PHP or ASP shell, although these will often have certain restrictions that will only allow certain file types, extensions, file names or contents.
File upload vulnerabilities are very common when conducting a penetration test against web applications, knowing how to bypass file restrictions is key as these will often result in a full system compromise.
Hammer is a command-line tool provided with Red Hat Satellite 6. You can use Hammer to configure and manage a Red Hat Satellite Server through either CLI commands or automation in shell scripts. The following cheat sheet provides a condensed overview of essential Hammer commands. See the Hammer CLI Guide for more information on Hammer.
To avoid compression (blurriness) and upload failure issues, make sure your file aspect ratio, size and format is one of those listed above. You can use a number of tools to resize, cut or format your media files before upload.
Both are not yet supported by Instagram on their Web platform and are intended to be shot and uploaded from mobile devices. The optimal sizes for Live Videos and Reels are 1080:1920px and are shot vertically similar to Stories.
scrabblecheat.io has advanced OCR technology for reading your Scrabble board from a screenshot. While we have spent countless hours testing our OCR and help algorithms, it's impossible to test every Scrabble board on every device. Changelog and known issues
The Snyk CLI is an excellent and powerful tool to scan your applications, containers, and infrastructure as code for security vulnerabilities. In this cheat sheet, we will look at the most powerful features our CLI has to offer. You can use the CLI for scanning and monitoring on your local machine, but you can also integrate it into your pipeline. Regardless of how you use it, the Snyk CLI is the go-to tool to test, monitor, and remediate known vulnerabilities in your applications. 041b061a72