A disclosed but not patched vulnerability in a system or device is known as a “zero-day exploit”. In other words, a Zero Day exploit refers to a security exploit that is newly found by a security researcher and does not have a security patch at the moment. It is also referred to as the “0day Exploit”.
A zero-day can be found in software, applications, and hardware. Zero-day can affect from small-sized printers to a big rocket that flies to the moon. Hackers typically use exploit code to take advantage of zero days to gain access to the system or device. Most of the time the exploit code may not be published by the attacker. It may take days or even months to release a zero-day exploit. Nowadays, many product vendors or tech companies accept vulnerability reports from cybersecurity researchers and mitigate those reported vulnerabilities internally without disclosing them to the general public. Once the patch for zero-day is released by the company and then detailed report for zero-day is also published as an advisory.
What can be affected by Zero Day Exploit?
Any software, mobile applications, web application, thick/thin clients, network devices, Operating Systems, etc can have zero-day exploit at any time in them. Cybersecurity professionals keep finding security bugs or vulnerabilities regularly in those systems to gain access to them, escalate their privileges, read other users’ data, etc. Not only do ethical hackers find zero days, but sometimes cyber criminals or black hat hackers try to find zero-day exploits in systems for different purposes such as to get revenge on them, attack other systems from that system, test their skills, steal valuable information, doing financial frauds, etc.
How Zero Day attacks are exploited?
Most of the time zero-day attacks are exploited in mass when the exploit code is released by a bad actor. Sometimes attackers may not release the exploit details to the general users and the attack may have been in practice for a long time and it is unnoticed. Once the exploit method or code is released then the other parties may check for vulnerable systems on the entire internet using different tools and the exploit in mass. You can check this post to know more about different tools used in penetration testing.
Example of zero-day attack
The basic illustration of how an application can face zero-day attacks is shown in the steps below.
- Your programmers create an application, but they are unaware that the code has a flaw.
- A vulnerability is discovered by an attacker before developers have a chance to find or patch it.
- While the vulnerability is still active, this attacker creates malicious code and launches an attack.
- After the exploit, either the developer tracks down the exploitation or the users notice a data leak or identity theft.
In the above scenario, the attack is organized because of a lack of security assessment. Hence, it is very important to perform a security assessment of an application once it is deployed in live systems. A separate team of security researchers is a must to address this type of incident.
Impacts of Zero-Day Attacks
All the security vulnerabilities and security bugs have a set of impacts. The impact can depend upon different factors such as how much critical the system is, what type of data the system is holding, the number of users affected by that attack, etc. A few of the common impacts of zero-day attacks are listed below.
- Financial loss and data loss.
- Data theft of mass users.
- Exploitation on large scale affects users.
- Getting access to higher privilege in a system.
- Accessing systems without needing credentials
- Business loss or outage as the security patch is not available.
How to prevent a Zero Day attack?
As the name says zero-day attack is an attack or exploit which may not have an exact security patch at the moment. Hence, the best way of being safe from zero-day attacks is to invest in SOC/SIEM, system monitoring, log monitoring, log analysis, and hunting unusual activity in our assets or IT systems. Preventative security, the best way to minimize the harm caused by any attack on your system is to stop it before it even starts. The best action you can take to ensure the security of your system is to keep a reliable firewall and update the current version of the system to the latest one.
Some of the steps that can be carried out to minimize zero-day attacks are given below.
- Continuous logging and monitoring of all systems and devices.
- Keeping a record of the current version of all of your assets and regularly checking for new updates of those systems.
- Implement SOC (security operation center) and SIEM (security information and event management) systems to monitor suspected activities.
- Regularly get updated with security news, exploits, research, and vulnerabilities in different systems from different sources like exploit-db.com, update with newly published CVE’s, and keep checking blogs of individual vendors.
- Perform regular security assessments of network systems and applications.
- Use of a strong firewall to minimize the risk.
Zero day exploit examples
Let’s discuss a few zero-day exploits that have carried out huge impact on our cyber world. Below are a few of the zero-day exploits.
- Log4j Exploit – Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix releases 2.3.2 and 2.12.4) are vulnerable to a remote code execution (RCE) attack where an attacker with permission to modify the logging configuration file can construct a malicious configuration using a JDBC Appender with a data source referencing a JNDI URI which can execute remote code.
- EternalBlue Exploit (MS17-010) – Any system that uses the vulnerable version of SMBv1 (Server Message Block version 1) file-sharing protocol, including Windows operating systems, is vulnerable to this exploit. This exploit helps in gaining complete access to a target system.
- Solar Winds Remote code execution (CVE-2021-35211) – Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product leading to a Remote Memory Escape bug.
- Sony Zero Day Attack (2014) – In late 2014, a zero-day exploit affected Sony Pictures. The attack severely damaged Sony’s network and resulted in the disclosure of private company information on file-sharing websites. Information about upcoming films, business strategies, and the private email accounts of top Sony executives was among the compromised data. The specifics of the vulnerability that was attacked by Sony are still unknown.
How to identify zero-day vulnerability?
Zero Day Attacks are difficult to defend against by definition. The only sure way to know is to look into the past and examine the relevant network activity. The additional precautions can be.
- Regular scanning for vulnerabilities
- Patch management
- Threat detection and observation
