Apache Log4j Vulnerability CVE-2021-44228: How to minimize your exposure

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Gabi (Grisel) Lavecchia
Gabi (Grisel) Lavecchia

Apache Log4j is a popular logging library used in many Java-based applications. It provides the ability to log messages in different formats and supports logging in various applications. Recently, it was found that a major Log4j vulnerability, CVE-2021-44228, allows attackers to execute code within the application remotely. With the scale of Log4j, this vulnerability was a high stakes security concern for thousands, if not hundreds of thousands of organizations. Organizations need to minimize their external exposure to the Apache Log4j vulnerability. This article discusses the vulnerability, how it works, and steps to minimize your exposure to the Apache Log4j vulnerability. We will also discuss the importance of keeping your applications up to date and how to ensure that your applications are secure from external threats.

What is the CVE-2021-44228 vulnerability?

CVE-2021-44228 is a critical remote code execution vulnerability recently found in Apache Log4j. This critical vulnerability allows attackers to remotely execute arbitrary code within the application. The attacker must send a malformed request to the vulnerable application to exploit this vulnerability. As a result, the application will fail to process the malformed request, which can cause the application to fail, leading to remote code execution within the application.

How does the CVE-2021-44228 vulnerability impact a company?

ovalsec - How to minimize your external exposure-Blog post- EASM - external attack surface management
Source: JetPatch

The CVE-2021-44228 vulnerability allows attackers to execute malicious code on a vulnerable system remotely, gain access to sensitive information, disrupt operations, or even take control of the affected system. The loss or theft of sensitive data could lead to financial loss, customer trust, and legal penalties. The attacker could disrupt the company’s operations, leading to further financial losses and damage to the company’s reputation.


Steps to Minimize your External Exposure

ovalsec - How to minimize your external exposure-Blog post- EASM - external attack surface management
Source: Audacix

1.    External attack surface risk detection

External attack surface risk detection identifies and assesses potential vulnerabilities in an organization’s external-facing systems, networks, and assets. To minimize exposure to external attack surfaces, organizations can use the following methods: Vulnerability scanning, Penetration Testing, Security Information and Event Management (SIEM), Security orchestration and automation, and Network Segmentation. Once vulnerabilities and potential attack surfaces have been identified, organizations can prioritize and address them through patching, configuration changes, or other mitigation strategies. Additionally, it is important to keep your software and systems up-to-date and monitor any suspicious activity.

2.    Keep applications updated

Keeping applications updated minimizes exposure to the Apache Log4j vulnerability (CVE-2021-44228). To ensure that your applications are updated to the latest version of Log4j, you should review the dependencies of your applications and identify any that use Log4j. After upgrading, you can also test your applications to ensure they continue functioning as expected.

3.    Remediate vulnerable apps

To remediate vulnerable apps and minimize exposure to the Apache Log4j Vulnerability (CVE-2021-44228), it is important to identify affected applications by reviewing the dependencies of your applications and identifying any that use Log4j versions 2.13.2 and below. Once identified, you can upgrade to the latest version, including the vulnerability’s fix, and don’t forget to test the updated application to ensure it continues functioning as expected. You should also monitor your systems for any suspicious activity related to the vulnerability, such as attempts to exploit it.

4.    Implementing secure coding practices

Implementing secure coding practices minimizes Apache Log4j Vulnerability exposure (CVE-2021-44228). These practices can help to reduce the likelihood of introducing vulnerabilities into the codebase in the first place. Some examples of secure coding practices that can be used include input validation to ensure that all input data meets the expected format and type and proper error handling to prevent exposure of sensitive information. You can also use secure logging practices such as sanitizing sensitive data and logging only the necessary information. You should also ensure that all components are configured securely, and that default settings are changed while also conducting regular code reviews to identify and fix any vulnerabilities before they can be exploited.

5.    Patching systems to fix known vulnerabilities

Patch affected systems as soon as a patch is made available because it’ll address the specific vulnerability by modifying the affected software, making it more difficult for an attacker to exploit it. In general, to minimize exposure to vulnerabilities, it is important to keep all systems and software up to date with the latest patches and security updates. Additionally, it is the best practice to monitor for and investigate any suspicious activity on the systems and have an incident response plan in place.

6.    Monitor logs and network traffic for unusual activity

Monitoring logs and network traffic for unusual activity is important in minimizing exposure to the Apache Log4j Vulnerability. There are various practices, such as implementing a network intrusion detection system (NIDS), a host-based intrusion detection system (HIDS), or security information and event management (SIEM). These systems can help to aggregate and analyze log data from multiple sources and detect any attempts to exploit the vulnerability. However, monitoring logs and network traffic alone is not enough to fully protect your systems and should be used with other security measures such as patching systems, implementing firewalls, and having an incident response plan.


7.    Use a log management system

A log management solution can help companies aggregate and store log data from multiple sources in a central location which makes it easier to monitor and analyze the logs for any suspicious activity. Using log management tools can also help detect potential malicious attempts to exploit the vulnerability. Make sure to choose a log management solution with features such as event correlation, real-time log collection, and alerting. This allows you to quickly identify and respond to any suspicious activity, such as unauthorized access attempts, or attempts to exploit the vulnerability. You can also choose a log management solution with built-in security analytics and threat detection capabilities to help identify potential security threats and provide actionable insights.


In this post, we’ve briefly explained Apache Log4j Vulnerability CVE-2021-44228 and how it impacts businesses. Apache Log4j Vulnerability (CVE-2021-44228) poses a significant threat to organizations of all sizes and industries and

is crucial for cybersecurity leaders to prioritize the identification and remediation of the Apache Log4j Vulnerability (CVE-2021-44228) to mitigate the risk of attack. This should involve conducting a thorough audit of all internet-connected or public-facing applications, websites, and systems within their domain of responsibility, including self-hosted versions of vendor products and cloud-based services. Special attention should be given to systems that contain sensitive operational data, such as customer information and access credentials. security leaders need to take proactive measures to minimize their external exposure to this vulnerability by implementing best practices such as external attack surface management, software supply chain security, vulnerability scanning, and secure coding practices. Additionally, it is important to keep applications and systems up-to-date, regularly test backup and disaster recovery plans, and monitor for suspicious activity. By taking these steps, organizations can improve their overall security posture and reduce the risk of a ransomware attack.


Using Ovalsec External Attack Surface Protection Platform To Minimize Critical Zero-day CVEs Risk

Ovalsec’s external attack surface protection platform provides organizations with the most advanced risk detection techniques available today, enabling security teams to improve security and increase agility in preventing targeted attacks. Ovalsec platform adds zero-day critical priority CVEs such as Log4j, as they are discovered, scan for exploitable assets using Log4j, enabling security teams to focus on exploitable assets at risk first.
The platform is fully automated and enables security teams to speed up the remediation process and minimize the attacker’s advantage. By allowing organizations to gain full visibility on their external attack surface, close security gaps, and reduce the risk from targeted cyberattacks.


Topics: Log4j, External attack surface management, Zero-day CVEs, Vulnerability management, Open-source, ASM

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