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.
On Dec 9th, a critical zero-day vulnerability - CVE-2021-44228 - was announced concerning the Java logging framework - Log4j All current versions of log4j2 up to 2.14.1 are vulnerable. To remediate this vulnerability, please update to version 2.15.0 or later.
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.
To understand how Elastic is currently assessing internal risk of this vulnerability in our products please see the advisory here.
Authors and Contributors: As always, security at Splunk is a family business. Credit to authors and collaborators: Ryan Kovar, Shannon Davis, Marcus LaFerrera, John Stoner, James Brodsky, Dave Herrald, Audra Streetman, Johan Bjerke, Drew Church, Mick Baccio, Lily Lee, Tamara Chacon, Ryan Becwar. If you want just to see how to find detections for the Log4j 2 RCE, skip down to the “detections” sections.
Today (Dec.10, 2021), a new, critical Log4j vulnerability was disclosed: Log4Shell. This vulnerability within the popular Java logging framework was published as CVE-2021-44228, categorized as Critical with a CVSS score of 10 (the highest score possible). The vulnerability was discovered by Chen Zhaojun from Alibaba’s Cloud Security team. All current versions of log4j2 up to 2.14.1 are vulnerable. You can remediate this vulnerability by updating to version 2.15.0 or later.
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.
Earlier today, a serious flaw was discovered in the widely used Java logging library Apache Log4j. The vulnerability, ‘Log4Shell,’ was first identified by users of a popular Minecraft forum and was apparently disclosed to the Apache Foundation by Alibaba Cloud security researchers on Nov. 24, 2021. The vulnerability has the potential to allow unauthenticated remote code execution (RCE) on nearly any machine using Log4j.
