OpenNMS Remote Code Execution (RCE) Scanner

OpenNMS is an open-source network management platform used by enterprises around the world for monitoring large-scale IT infrastructures. It helps in managing network performance, fault detection, and traffic analysis, providing valuable insights for IT operations. The platform is employed by network administrators and IT professionals to ensure the smooth functioning of network systems through monitoring and alerting capabilities. OpenNMS can be deployed on various system architectures and integrates with diverse network devices and applications, making it a versatile choice for complex environments. It is often used in sectors requiring robust network surveillance, including telecommunications and data centers. OpenNMS's extensibility and scalability make it suitable for both small businesses and large, distributed organizations.

A Remote Code Execution (RCE) vulnerability allows an attacker to execute arbitrary code on a target system, potentially with elevated privileges. In the context of OpenNMS, this RCE vulnerability is exploitable through the Apache Log4j library version 2.14.1 and earlier. Attackers leveraging this vulnerability can send specially crafted requests to the OpenNMS application to execute arbitrary code. This vulnerability is critical due to the widespread use of the affected Log4j versions in various applications, not just OpenNMS. When exploited, it could allow unauthorized control over the compromised systems remotely. It is crucial to address this RCE vulnerability promptly to maintain system integrity and security.

The vulnerability in OpenNMS related to the Apache Log4j library involves JNDI (Java Naming and Directory Interface) injection via log messages. The endpoint '/opennms/j_spring_security_check' is used for the attack vector, typically targeted by sending crafted payloads that exploit the Log4j JNDI lookup feature. This feature, when used maliciously, can retrieve code from LDAP servers and execute it on the vulnerable host. Parameters such as 'j_username' in HTTP requests can be manipulated to include the JNDI payload, leading to execution of the remote code. This process typically requires interaction with the DNS to redirect to a malicious server hosting the attack code. The vulnerability relies on enabling message lookup substitution within the application, which is a default behavior in the vulnerable versions.

Exploitation of this RCE vulnerability can lead to severe consequences, including unauthorized access, data theft, privilege escalation, and complete system compromise. Attackers could gain control over affected hosts, using them as a pivot point to infiltrate deeper into the network. They may deploy malware, steal sensitive information, disrupt services, or even launch further attacks against other connected systems. If exploited in critical environments, this vulnerability can have significant operational and financial impacts. It is critical for organizations using vulnerable versions of OpenNMS to patch their systems and apply mitigations to prevent exploitation.

REFERENCES

• https://www.horizon3.ai/the-long-tail-of-log4shell-exploitation/
• https://www.opennms.com/en/blog/2021-12-10-opennms-products-affected-by-apache-log4j-vulnerability-cve-2021-44228/
• https://logging.apache.org/log4j/2.x/security.html
• https://nvd.nist.gov/vuln/detail/CVE-2021-44228