Graylog Remote Code Execution Scanner

Graylog is a leading open-source log management solution used by IT departments and developers across industries to identify and troubleshoot security issues, system improvements, and application errors. Offering a streamlined interface for managing and analyzing large volumes of log data, Graylog enhances operational efficiency and is crucial in DevOps practices for continuous delivery and integration. The platform provides real-time insights and customizable dashboards, making it a versatile tool for data analytics and threat detection. Favored in environments demanding high data integrity and resilient system architectures, Graylog is employed both on-premises and in cloud deployments. This software delivers robust search and alerting capabilities, enabling teams to respond swiftly to security events and system alerts.

The vulnerability involves exploiting Apache Log4j 2 library by controlling log messages or log message parameters, allowing for remote code execution when message lookup substitution is enabled. Attackers can trigger this vulnerability remotely if they can manipulate input fields that are subsequently logged by Graylog. These JNDI features in Log4j do not sufficiently guard against attacker-controlled LDAP and other endpoints. Consequently, this can lead to severe exploitation where malicious LDAP servers are used to feed harmful instructions or executables into the system. Due to its widespread usage in logging user activities, the attack surface for exploiting Log4j is significantly broad, impacting a wide range of industries.

Technically, the exploitation involves injecting specific payloads into log messages that are processed by the Log4j logging framework within vulnerable Graylog instances. The attack leverages the JNDI lookup feature in Log4j where inputs, often in the form of LDAP URLs, allow retrieval of Java classes. The endpoint affected largely includes those where user input is logged directly, and parameters are parsed by the Log4j2 library without proper validation. The vulnerability is particularly exacerbated in configurations where logging includes untrusted data sources or endpoints are accessible to remote users. The attack vector usually involves sending specially crafted requests to the vulnerable application, resulting in arbitrary code execution.

When successfully exploited, the potential impacts are severe, including unauthorized access to sensitive data, installation of malicious software, system compromise, and service disruption. Such an exploit can enable threat actors to execute instructions at the privilege level of the service, which potentially includes deploying ransomware or exfiltrating data. Organizational downtime and data breaches are common repercussions, causing financial and reputational damages. Moreover, this vulnerability highlights substantial risks in system components relying on external libraries, necessitating immediate patches and security assessments.

REFERENCES

• https://www.graylog.org/post/graylog-update-for-log4j
• https://logging.apache.org/log4j/2.x/security.html
• https://nvd.nist.gov/vuln/detail/CVE-2021-44228