The powerful and free, open-source payload deobfuscation tool is the first in a series of solutions to assist developers, AppSec professionals, and the open-source community. Ox4Shell is designed to confront what some are calling the “Covid of the Internet,” known as the Log4Shell zero-day vulnerability. To counter a very effective obfuscation tactic used by malicious actors, Oxeye’s new open-source tool (available on GitHub) exposes hidden payloads that are actively used to confuse security protection tools and security teams.
Critical level vulnerability
As reported by experts, 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. As part of a new open-source initiative for 2022, Oxeye unveils the first in a series of contributions designed to strengthen security efforts by deobfuscating payloads often coupled with Log4J exploits.
Exposing obscured payloads
Ox4Shell exposes obscured payloads and transforms them into more meaningful forms to clearly understand 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 uniquely identifies a compromised machine they’ve targeted. Ox4Shell allows you to comply with such lookup functions by feeding them mock data that you control.
Daniel Abeles, Head of Research at Oxeye said,
“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. 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.”