CVE-2025-34074 is a critical authenticated remote code execution (RCE) vulnerability affecting the Lucee server, an open-source CFML (ColdFusion Markup Language) application server maintained by Lucee Association Switzerland. The vulnerability resides in the administrative interface's scheduled task functionality, specifically accessible via /lucee/admin/web.cfm. An attacker with administrator-level credentials can exploit this flaw by configuring a scheduled job to fetch a remote .cfm file hosted on an attacker-controlled server. This file is then written directly into the Lucee webroot and executed with the privileges of the Lucee service account. The root cause is the lack of integrity checks, path restrictions, or execution controls on scheduled task fetches, allowing arbitrary code injection and execution. This vulnerability is distinct from CVE-2024-55354, indicating a separate design flaw. The affected versions include all 5.x and 6.x releases of Lucee that support scheduled task functionality. The CVSS 4.0 base score is 9.4, reflecting a critical severity due to network attack vector, low complexity, no user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability's nature and ease of exploitation by authenticated administrators make it a significant risk. The vulnerability is classified under CWE-94 (Improper Control of Generation of Code) and CWE-829 (Inclusion of Functionality from Untrusted Control Sphere), highlighting insecure code generation and untrusted input execution. The lack of patch links suggests that a fix may not yet be publicly available, emphasizing the need for immediate mitigation and monitoring.

For European organizations, this vulnerability poses a severe threat, especially those relying on Lucee for web application hosting and backend services. Successful exploitation can lead to full compromise of the affected server, allowing attackers to execute arbitrary code with service-level privileges. This can result in data breaches, service disruption, lateral movement within networks, and potential deployment of ransomware or other malware. Given the administrative interface requires authentication, insider threats or compromised administrator accounts are primary attack vectors. The impact extends to confidentiality (exfiltration of sensitive data), integrity (tampering with application logic or data), and availability (service outages or destruction). Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often use CFML-based applications, are particularly at risk. The vulnerability's exploitation could undermine trust in digital services, cause regulatory compliance violations under GDPR, and lead to significant financial and reputational damage.

1. Immediate mitigation should focus on restricting administrative interface access to trusted networks and personnel only, employing network segmentation and VPNs. 2. Enforce strong multi-factor authentication (MFA) for all administrator accounts to reduce the risk of credential compromise. 3. Monitor scheduled task configurations regularly for unauthorized or suspicious entries, especially those fetching remote .cfm files. 4. Implement strict file integrity monitoring on the Lucee webroot to detect unexpected file creations or modifications. 5. If possible, disable or limit the use of scheduled task functionality until a patch is available. 6. Apply the principle of least privilege by running the Lucee service under a minimally privileged account to limit the impact of potential exploitation. 7. Maintain up-to-date backups of critical data and configurations to enable recovery in case of compromise. 8. Stay informed on vendor advisories for patches or updates addressing this vulnerability and apply them promptly once released. 9. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious scheduled task requests or payloads. 10. Conduct regular security audits and penetration testing focused on administrative interfaces and scheduled task features.