Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

Log4j Log4Shell 0-Day Vulnerability: All You Need To Know

Last Thursday, a researcher from the Alibaba Cloud Security Team dropped a zero-day remote code execution exploit on Twitter, targeting the extremely popular log4j logging framework for Java (specifically, the 2.x branch called Log4j2). The vulnerability was originally discovered and reported to Apache by the Alibaba cloud security team on November 24th. MITRE assigned CVE-2021-44228 to this vulnerability, which has since been dubbed Log4Shell by security researchers.

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

On Thursday, December 9, a zero-day vulnerability CVE-2021-44228 (a.k.a. Log4Shell, LogJam, and Log4j) was made public. This vulnerability impacts Apache Log4j versions 2.0-beta9 to 2.14.1, and it has the highest possible CVSS score of 10.0. As of today, it is widely regarded as one of the most dangerous and widespread vulnerabilities to date.

Find and fix the Log4Shell exploit fast with Snyk

Even if you tried VERY hard to enjoy a quiet weekend, chances are that this plan was interrupted at least once by the new Log4Shell zero-day vulnerability that was disclosed on Friday (December 10, 2021). The new vulnerability was found in the open source Java library log4j-core which is a component of one of the most popular Java logging frameworks, Log4J.

New test added for actively exploited critical CVE-2021-44228 Apache Log4j RCE

Thanks to Detectify Crowdsource hackers, Detectify quickly developed a security test to detect Critical vulnerability CVE-2021-44228 Apache log4j RCE. This vulnerability has set the internet alight over the past few days. Right now, exploit developers and security researchers are still understanding the potential capabilities provided by the vulnerability. Detectify received a working POC for this critical 0-day vulnerability from the Crowdsource community on Friday.

CVE-2021-44228: Log4J2 Remote Code Execution

On Dec. 9, 2021, a remote code execution (RCE) vulnerability in Apache log4j 2 was identified, (Dubbed “Log4Shell” by researchers), affecting massive amounts of servers all over the world. As this vulnerability gains high traction worldwide, it’s important to note, that not only internet facing java applications are vulnerable, as user input can traverse to another non-internet facing machines and exploit these as well.

Forescout's Response to Apache Log4j Vulnerabilities

Updated 12/20/21 On December 9, 2021, Apache published a zero-day vulnerability (CVE-2021-44228) for Apache Log4j being referred to as “Log4Shell”. This “critical” vulnerability (CVSS score: 10) allows a remote attacker to take control of an affected system. When exploited, this vulnerability allows an attacker to run arbitrary code on the device, giving full control over to the attacker.

Detection of Log4Shell Vulnerability and Exploitation Using Devo

A critical vulnerability in the popular log4j library is currently being actively targeted on a broad global scale and possibly exploited based on advisories from multiple CERTs and vendors: CISA, Apache, etc. This Java library is integrated into many IT and DevOps tooling and workflows. On Dec 10, 2021, Apache released version 2.15.0, fixing CVE-2021-44228 (dubbed Log4Shell) an RCE with a maximum CVSSv3 score of 10.

Critical vulnerability in log4j, a widely used logging library

Security researchers recently disclosed the vulnerability CVE-2021-44228 in Apache’s log4j, which is a common Java-based library used for logging purposes. Popular projects, such as Struts2, Kafka, and Solr make use of log4j. The vulnerability was announced on Twitter, with a link to a github commit which shows the issue being fixed. Proof-of-concept code was also released to github which shows that the vulnerability is trivial to exploit.