Fighting Log4j


Oxeye has unveiled the first 2022 open-source initiative with the introduction of Ox4Shell. To counter a very effective obfuscation tactic used by malicious actors, Oxeye’s new open-source tool (available on GitHub) exposes hidden payloads which are actively being used to confuse security protection tools and security teams.

Organizations globally continue to experience remote code attacks and the exposure of sensitive data due to the pervasive Log4Shell vulnerability. Discovered in Apache’s Log4J, a logging system in widespread use by web and server application developers, the threat makes it possible to inject text into log messages or log message parameters, then into server logs which can then load code from a remote server for malicious use. Apache has given Log4Shell a CVSS severity rating of 10 out of 10, the highest possible score. Since then, researchers found a similar vulnerability in the popular H2 database. The exploit is simple to execute and is estimated to affect hundreds of millions of devices.

According to Jonathan Care, Senior Director Analyst at Gartner, “The Log4j vulnerability is extremely widespread and can affect enterprise applications, embedded systems, and their sub-components. Java-based applications including Cisco Webex, Minecraft, and FileZilla FTP are all examples of affected programs, but this is by no means an exhaustive list. The vulnerability even affects the Mars 2020 helicopter mission, Ingenuity, which makes use of Apache Log4j for event logging.”

Ox4Shell exposes obscured payloads and transforms them into more meaningful forms to provide a clear understanding of what threat actors are trying to achieve. This allows concerned parties to take immediate action and resolve the vulnerability.

The Log4j library has a few unique lookup functions that permit users to look up environment variables, Java process runtime information, and so forth. These enable threat actors to probe for specific information that can uniquely identify a compromised machine they’ve targeted.

“Difficulties in applying the required patching to the Log4Shell vulnerability means this exploit will leave gaps for malicious attacks now and in the future. The ability to apply obfuscation techniques to payloads, thereby circumventing the rules logic to bypass security measures also makes this a considerable challenge unless the proper remedy is applied,” said Daniel Abeles, Head of Research at Oxeye. Deobfuscation will be critical to understanding the true intention(s) of attackers. Ox4Shell provides a powerful solution to address this and as a supporter of the open-source community, we are proud to contribute and make it available through GitHub.”