Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

After successful deployment to Arctic Wolf’s customer community of more than 2,300 organizations worldwide, today we are making “Log4Shell Deep Scan” publicly available on GitHub. Log4Shell Deep Scan enables detection of both CVE-2021-45046 and CVE-2021-44228 within nested JAR files, as well as WAR and EAR files.

A critical vulnerability has been recently discovered in the Apache Log4j Java logging library (CVE-2021-44228), a library used in many client and server applications. The Log4j library is commonly included in Java based software including multiple Apache frameworks such as Struts2, Solr, Druid and Fink. The library provides enhanced logging functionality for Java applications and is commonly used in business system development.

While many organizations are patching the two recent Apache Log4j vulnerabilities (CVE-2021-44228 and CVE-2021-45046), attackers have been racing to exploit them to deliver malware, such as botnets, backdoors, and cryptominers. Among the threats delivered using Log4Shell exploits, a new ransomware family was found by Bitdefender: Khonsari.

The Apache Log4j vulnerability has been assigned the most critical cyber threat rating of CVSS 10. For a concise overview of the zero-day, and to learn how to secure your systems against its exploitation, all of the popular FAQs concerning this vulnerability have been conveniently compiled in this post.

Is it just me or is the announcement of a significant CVE becoming a holiday tradition? Discovered on December 9, 2021 by Minecraft players, the Apache Log4Shell vulnerability is a uniquely insidious because it infects servers which are traditionally well insulated from attacks and perceived as unreachable by an intruder and not at risk for CVEs. Log4Shell is an entirely different can of works that proves this assumption wrong.

We recently discussed some methods for detecting the Log4j exploit, and we’ve now developed another method that everyone running Zeek® or a Corelight sensor can use. Our new approach is based on the rarity of legitimate downloads of Java via LDAP. Zeek does not currently have a native LDAP protocol analyzer (though one is available if you are running Spicy). This will not stop you from detecting this exploit downloading Java over LDAP, though. To see how, read on.

In quick succession in December, The Apache Software Foundation released information on two critical vulnerabilities in its Log4j Java-based library. The first vulnerability CVE-2021-44228, also known as Log4Shell or LogJam, was reported as an unauthenticated remote code execution (RCE) vulnerability. By exploiting how the library logs error messages, it could lead to a complete system takeover.

On Nov. 24th 2021 a severe security vulnerability, called “Log4Shell”, has been reported in the JAVA framework “Log4J” 2.x which is widely used for event logging in JAVA applications worldwide. The vulnerability allows cyber-attackers to execute arbitrary code by injecting it into a logging process implemented in Log4J. The “Log4Shell” vulnerability allows complete server takeover by the attackers.