What Is Zero-Day Vulnerability? A Threat You Need to Be Aware Of

Security vulnerabilities are a consistent threat to cybersecurity.

Attackers exploit them to gain unauthorized access to your assets and fulfill their malicious intent. When such vulnerabilities are newly discovered, they serve as a wild card for attackers to penetrate your systems and catch you by surprise.

At times there can be a slight delay in releasing the patch and fixing the security weakness. An attacker can reap the benefit of such an opportunity and exploit the zero-day vulnerability to access your assets.

You should prevent malicious security threats at all times. It’s also advisable to have an incident response strategy to handle the adversity if it comes knocking on your digital doorstep. 

What is zero-day vulnerability?

A zero-day vulnerability is a newly identified security weakness in a software or system that hasn’t received the blessing of a patch to keep attackers at bay. 

It can be a software vulnerability unknown to those interested in remediating it. A security bug discovered or disclosed before its patch came into light, or a new security weakness where the company released the patch but wasn’t implemented through an update. 

Zero-day vulnerabilities have the potential to cause severe damage to your information and sensitive data. When such situations prevail, being proactive and reactive will help you avoid or minimize the extent of its damage.

Scan your assets periodically to check for security vulnerabilities and identify any gaps you can bridge. Vulnerability scanners are a trustable and proactive software solution to deal with zero-day threats. The vulnerability scanner might not unveil the actual zero-day vulnerability as its signature is unknown. But it’ll help you fix known vulnerabilities that attackers might use to conduct a zero-day exploit first hand.

Make sure you are set with a robust vulnerability management program in your organization. The program should include vulnerability scanning, prioritization, remediation, patching, and reporting, allowing you to be proactive in identifying new vulnerabilities and managing them effectively. 

Another important aspect in preventing exploits on zero-day vulnerabilities is being reactive, i.e. installing security updates as they are released. A software update contains a security patch that fixes a software application or a system security’s weaknesses and builds a strong line of defense against zero-day exploits.

Most security solution providers will release a solution as soon as a new vulnerability embarks on cyberspace. Implement those solutions to mitigate the security risk of a zero-day attack. 

How to protect against zero-day exploits

Detection of zero-day vulnerability is the first step in protecting your assets against it. These vulnerabilities often challenge antivirus or intrusion detection systems, as they don’t have a known signature.

The best solution in such situations is security information and event management (SIEM). SIEM software will help the security teams to identify any anomalies detected in the system and gather threat intelligence. These anomalies may be unknown threats, unapproved access, or new malware, including worms, ransomware, or other malicious programs. With digital forensic analysis, SIEM software will better protect the teams against zero-day vulnerabilities.

It’s tricky to defend against zero-day vulnerabilities as they are unknown to people interested in fixing them. But there are a few protective measures you can take to avoid an encounter.

• Conduct regular vulnerability scanning with a black box scanner and fix known vulnerabilities.
• Keep all operating systems and software patched and apply the zero-day patch as soon as it’s released.
• Use virtual local area networks to segregate sensitive traffic between servers.
• Apply encryption and authentication to network traffic using IP security protocols.
• Use a network security key with security schemes such as Wi-Fi Protected Access 2 to ensure protection against wireless-based attacks.
• Adopt intrusion detection and prevention systems to receive alerts about suspicious activities happening on the sidelines of a zero-day attack.
• Control access to corporate infrastructure with network access control (NAC) software.
• Train teams to develop a strong understanding of social engineering, phishing, and malicious tactics of threat actors.
• Instate layered security controls such as perimeter firewall, endpoint protection software, and more.

At times, zero-day exploits might impact your assets even after ensuring the best information security practices. Nevertheless, these best practices will prevent your systems from attackers using the same zero-day exploit after the vulnerability is patched.

Common methods of executing a zero-day exploit

The first thing that follows setting preventive measures is staying informed about the know-hows of a zero-day exploit. You should be aware of the common methods through which attackers can create a zero-day attack on your assets.

There are a variety of ways in which a zero-day attack can affect your assets, the common ones are as follows:

• Spear phishing: Attackers target a specific and authoritative individual and try to trick them into acting on a malicious email. Threat actors may study the target and acquire knowledge about them using social engineering tactics.
• Phishing: Threat attackers send spam emails to many people within an organization, intending to trick some to dive into the malicious link embedded in the mail.
• Exploit kits in compromised websites: Bad actors take over a website to embed a malicious code or an advertisement that redirects the visitor to the exploit kit server.
• Brute force: Attackers use brute force to compromise a server, system, or network and use the exploit to penetrate your assets.

Examples of zero-day attacks

One of the most recent examples of zero-day vulnerability rests within Microsoft Exchange. On March 2, 2021, the company warned about four zero-day vulnerabilities being exploited in the wild against US governmental agencies. Microsoft urged their customers to apply patches as quickly as possible, but as it often happens with zero-days, cybercriminals are fast to exploit them.

Other well-known zero-day attacks include:

• Stuxnet: It’s a malicious worm that targeted computers used for manufacturing purposes. Iran, India, and Indonesia were some regions where it made an impact. The primary intention of Stuxnet was to disrupt Iran’s nuclear program by infecting uranium enrichment plants. The worm infected zero-day vulnerabilities in programmable logic controllers (PLC) running in industrial computers through vulnerabilities in Siemens software.
• RSA: Taking undue advantage of an unpatched vulnerability in Adobe Flash Player, malicious hackers gained access to RSA’s network. Hackers employed a spamming and phishing method, where they sent emails with a Microsoft Excel spreadsheet attachment to a small group of RSA employees. The spreadsheet contained an embedded Flash file, exploiting the zero-day vulnerability in Adobe Flash Player.
• Operation Aurora: This cyber attack targeted zero-day vulnerabilities in Internet Explorer and Perforce. Google used Perforce to manage its source code then. It was aimed at the intellectual property of major enterprises like Google, Adobe, Yahoo!, and Dow Chemicals.

Save yourself from zero-days

Zero-day vulnerabilities are an alarming concern for security researchers. They can catch an organization by surprise and yield damage despite them being on point with the best cybersecurity practices.

You must always be proactive in deploying and implementing patches of new vulnerabilities, and at the same time, be prepared to handle adversity if it comes. 

Learn more about vulnerability scanning software to detect known vulnerabilities and prevent them from being exploited on the sidelines of a zero-day attack.