CVE-2025-67900 is a vulnerability identified in NXLog Agent versions prior to 6.11, classified under CWE-829 (Inclusion of Functionality from Untrusted Control Sphere). The issue arises because NXLog Agent loads a configuration file specified by the OPENSSL_CONF environment variable without sufficient validation or restriction. This environment variable controls the OpenSSL configuration, which governs cryptographic operations such as certificate validation, cipher selection, and protocol settings. An attacker with local access can set or manipulate OPENSSL_CONF to point to a malicious configuration file, thereby influencing the cryptographic behavior of NXLog Agent. This can lead to severe consequences including interception or tampering of log data, execution of arbitrary code, or denial of service. The vulnerability has a CVSS v3.1 score of 8.1, indicating high severity, with an attack vector limited to local (AV:L), high attack complexity (AC:H), no privileges required (PR:N), and no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the vulnerable component, and it impacts confidentiality, integrity, and availability at a high level. No patches are currently linked, but upgrading to version 6.11 or later is implied as the fix. No known exploits have been reported in the wild yet, but the potential for exploitation exists especially in environments where local access can be obtained or where environment variables can be manipulated by untrusted users or processes.

For European organizations, the impact of CVE-2025-67900 is significant due to the critical role NXLog Agent plays in log management and security monitoring. Exploitation could allow attackers to manipulate cryptographic settings, potentially bypassing security controls, intercepting sensitive log data, or injecting malicious data into logs. This undermines incident detection and response capabilities, leading to prolonged undetected breaches. The high severity and scope change mean that the compromise could extend beyond the NXLog Agent process to affect system-wide security posture. Industries with stringent compliance requirements such as finance, healthcare, and critical infrastructure in Europe would face increased risk of regulatory penalties and operational disruption. Additionally, the local attack vector suggests that insider threats or attackers who gain initial foothold on a system could leverage this vulnerability to escalate privileges or maintain persistence. The lack of known exploits currently provides a window for proactive mitigation before widespread exploitation occurs.

1. Upgrade NXLog Agent to version 6.11 or later as soon as possible to ensure the vulnerability is patched. 2. Restrict local access to systems running NXLog Agent to trusted personnel only, minimizing the risk of environment variable manipulation. 3. Implement strict environment variable sanitation and monitoring on hosts to detect unauthorized changes to OPENSSL_CONF. 4. Use application whitelisting and integrity monitoring tools to detect unauthorized modifications to configuration files and binaries. 5. Employ least privilege principles for service accounts running NXLog Agent to limit the impact of potential exploitation. 6. Conduct regular audits of system environment variables and configurations related to cryptographic libraries. 7. In environments where upgrading immediately is not feasible, consider isolating NXLog Agent hosts and applying host-based intrusion detection to identify suspicious activity. 8. Educate system administrators and security teams about the risks of environment variable manipulation and the importance of securing local access.