A Guide to Zero-Day Vulnerabilities: The Invisible Threat

Zero-day vulnerabilities are unknown threats to your data. Having any data online poses many threats to cybersecurity, but what makes zero-day vulnerabilities so unique is that you can do everything correctly and will still not be completely secure. Zero-day threats can be traced to the dark web, where information is available for purchase by hackers that will help them break through cyber defenses. The security flaw may be recently known to the software vendor, but with no patch in place, the risk is significant. The name “zero-day” refers to the fact that the vendor has learned of the flaw, but has had “zero days” to respond. Hackers can take advantage at just the right moment.

How Zero-Days Work

A zero-day vulnerability begins with a software developer unknowingly releasing insecure code (the testing will likely show no issues). A malicious cyber actor discovers the flaw and exploits it, selling the information on the dark web or using it himself, often before the developer is even aware of the vulnerability. After this, the vulnerability will be discovered and disclosed by the developer, but in many cases, no patch will be developed yet. A security patch is developed and released as quickly as possible, and once that happens the security patch is deployed to all users.

The Vulnerability Ecosystem

There are several different roles in the vulnerability ecosystem.

• Hackers: hackers have different motivations for carrying out zero-day attacks. Some are cybercriminals who are usually after financial gain, either from the attack itself (gaining personal information which they can use themselves) or the sale of the information. Other hackers are motivated by political or social causes and want to draw attention to these causes. Others are focused on espionage, looking to gain information about a business or individual.
• Software Vendors: software vendors are often unaware that the software they are marketing has a zero-day vulnerability. In most cases, the developer who has put the software through the testing process has no knowledge of the vulnerability. As soon as developers become aware of the vulnerability, they make sure to get the information out to the vendors who can then notify their customers. The quicker a vendor is able to let the consumers know, the better.
• Security Researchers: Security researchers are always on the lookout for potential zero-day attacks which they can report to the software developers. Researchers look for malware characteristics based on how the users are interacting with the system. Machine learning has been extremely beneficial in helping security researchers identify threats, but a hybrid of different detection systems is often the most effective course of action.

There is an ecosystem where zero-day exploits are bought and sold, usually anonymously on the dark web. This is primarily used by cybercriminals who are both selling and buying the information they can then use for cyberattacks. Often, large sums of money are exchanged with the incentive to act on the information quickly, because once the threat is discovered and the patch is released, it is no longer useful to criminals.

There is also an ethical debate surrounding zero-day discoveries. The most dangerous part of a zero-day discovery is that users have “zero days” to apply a patch and protect themselves. If a researcher discovers a security flaw before a round of attacks and patches it, are they obligated to let the software users know? When should the public be made aware of potential zero-day threats? The answer is murky and still debated in many software companies.

Detecting and Preventing Zero-Days

The challenge in detecting zero-day vulnerabilities is simply that the cyber criminals have the information about the vulnerability before those with the ability to patch it. If the researchers are able to identify the vulnerability prior to the criminals, there is no risk, as the patch can be deployed without issue. However, this is not always the case, and organizations will need to take other strategies to mitigate their risk.

• Timely Patching and Updating is Crucial

Many users tend to put off updating their devices and software, simply because it feels like a hassle. However, to avoid the risk of serious fallout from a zero-day threat, any updates or patches put out by a software company should be implemented immediately, even if they do not seem urgent. All software and operating systems should always be kept up to date. The more current you are, the more protected you are.

• Only Install What You Need

The more software you have, the more vulnerable you are. You can keep your network safer by only having the necessary applications on your system. If you are no longer using an application, delete it from your device.

• Use Firewalls and Antivirus Software

Every organization should insist that firewalls are used on all devices. Firewalls play an essential role in protecting against any threats, including zero-day threats. Firewalls can be configured to only allow necessary transactions, which will greatly reduce your risk.

• Make Sure All Users are On Board

If only half of your employees are implementing best practices in cyber security, your system will not be protected. Zero-day attacks capitalize on human error. Make sure all employees and users understand the best practices in cybersecurity and are implementing them daily.

Zero-day vulnerabilities, since they do not give you knowledge about the threat until it is too late, can be scary to think of in terms of cybersecurity. But by being aware, looking for suspicious activity, and always implementing patches and upgrades, you can keep your data as safe as possible. Cyber threats are always evolving and it’s important to implement best practices. To learn more about how to keep your information safe, check out our AccuShred blog.