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Chaos Before Christmas: Exploitation of the Log4j Vulnerability

A security vulnerability is a system misconfiguration or a flaw in the software code that attackers exploit to gain unauthorized access to a system or network. Although these bugs or errors in the software implementation, design, or architecture are not inherently harmful, they enable the attacker to leverage privileges and authorizations to compromised assets and systems if left unaddressed.

On the other hand, zero-day vulnerabilities refer to those flaws in the software or network that remain unknown until its exploitation. Because of the nature of these vulnerabilities, security patches are not immediately available. As a result, hackers who discover zero-day vulnerabilities have the upper hand in disrupting critical business operations. It takes companies an average of 97 days to apply, test, and fully deploy patches to combat zero-day vulnerabilities.

Recent large-scale security incidents have shown that many third-party managed service providers lack proper visibility into crucial portions of their operations. In addition, many often lack the basic security best practices, thus allowing threat actors to infiltrate legitimate code bases and corrupt critical processes. Therefore, exploiting the zero-day vulnerabilities within software and supply chain infrastructures is gaining popularity.

This month, one of the most lethal zero-day discoveries, causing a considerable uproar worldwide, is the Apache Log4j zero-day vulnerability. This article will explore the structural weaknesses associated with the vulnerability, its exploitability levels, and its impact on the corporate computing environment.

Exploring the Apache Log4j Vulnerability

Developed by the Apache Foundation, Log4j is an open-source Java logging library. It is widely used in many applications and as a dependency in numerous cloud services and enterprise applications such as iCloud, Minecraft, Steam, Cisco, Cloudflare, ElasticSearch, Red Hat, Tesla, Twitter, Amazon, and more.

On December 9, 2021, Chen Zhaojun of the Alibaba Cloud Security Team discovered the Log4j vulnerability. After detecting the vulnerability on Minecraft, the general opinion was that it affected only the gaming platform. However, further scrutiny revealed that this vulnerability could affect any software using the Log4j library.

The Apache Log4j vulnerability (CVE-2021-44228), also referred to as Log4Shell or LogJam, falls under Remote Code Execution (RCE) class vulnerability. Additionally, the zero-day vulnerability entered the limelight, as attackers are actively exploiting this vulnerability to execute arbitrary code and take over the system. As a result, cyber experts have assigned the highest criticality level designation to the Apache Log4j library.

According to security researchers, attackers target the Log4j library with a single text string to exploit its vulnerability, thus triggering applications powered by the library to reach out to a malicious external host. As a result, the zero-day vulnerability entered the limelight, as attackers are actively exploiting this vulnerability to execute arbitrary code and take over the system. As a result, cyber experts have assigned the highest criticality level designation to the Apache Log4j library.

Impact on Corporate Infrastructure 

According to security experts, the Log4j zero-day vulnerabilities could have long-lasting effects on businesses of any size. Despite the widespread use of the Log4j library in enterprise Java software, it is challenging to quantify the impact because of its deployment methodology. However, failing to patch this flaw on time can lead to significant cyberattacks or data breaches.

Hackers can exploit the Log4j zero-day vulnerability to steal your company’s data, your employees, and your customers. The 2021 WatchGuard Internet Security report states that zero-day malware comprised 74% of all threats. Additionally, because there is a small-time window to fix the anomaly, attackers can take unauthorized control, accessing your network, server, program, website, or any other system to cause loss of productivity.

In addition, they can deploy phishing or malware to send malicious messages to your contacts. Such an attack could cause financial loss or present legal complications and damage the organization’s reputation.

Mitigating the Log4j Zero-day Vulnerability

Log4j poses a severe risk to organizations using the logging library version 2.0 to 2.14.1. The reason behind the severity of this vulnerability is that even an inexperienced hacker can execute an attack successfully. For example, hackers could take over the affected server with a Remote Code Execution attack. Furthermore, the number of Log4j exploitations has increased sharply since its discovery, as attackers are scouring the internet for vulnerable services and applications. Therefore, organizations must check whether this zero-day vulnerability affects them and apply necessary patches and security measures to prevent and mitigate any attack.

The Latest Guidelines for Mitigation

  1. Prepare a list of any external-facing devices that use the Log4j open-source library.
  2. Upgrade to Log4j version 2.15.0, or immediately implement recommended mitigations from appropriate vendors.
  3. Install a web application firewall (WAF) and set automatic rule updates for your security operation center (SOC) to concentrate on fewer crucial alerts.
  4. Organizations (and their third-party suppliers) should ensure that their SOC scrutinizes and responds to every alert on the devices containing the Log4j vulnerability.


The increasing sophistication of cybersecurity incidents, including discovering newer and more lethal vulnerabilities, constantly changes the cyber threat landscape. As a result, threat actors are working overtime to devise scalability methods of leveraging weaknesses and gaps in IT infrastructures. For example, the log4j zero-day vulnerability has shaken the world, reiterating the need for robust cybersecurity practices and incident response plans to save the day. Therefore, organizations running this open-source library must upgrade and check their system to detect and remove any anomaly on time.

All in all, corporate security teams must figure out disrupt and deter threat actors and protect corporate assets from exploitation. It all boils down to having a robust vulnerability management process and framework capable of detecting, responding, and recovering from security risks that impact business continuity. Therefore, engaging with a reliable cybersecurity advisor with expertise in vulnerability management helps verify your security posture against the log4j vulnerability and any future exploitation.

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