CVE-2025-56425 is a critical command injection vulnerability affecting the AppConnector component of the enaio document management system across multiple versions (10.10.0.183 and earlier, 11.0.0.183 and earlier, and 11.10.0.183 and earlier). The flaw resides in the /osrest/api/organization/sendmail REST API endpoint, which improperly sanitizes input, allowing unauthenticated remote attackers to inject arbitrary SMTP commands. This injection can manipulate the SMTP communication process, potentially enabling attackers to send unauthorized emails, exfiltrate sensitive information, or disrupt email services. The vulnerability is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command), indicating that the input is not properly escaped or validated before being passed to the SMTP command interface. The CVSS v3.1 base score of 9.1 reflects the vulnerability’s network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and high availability impact (A:H). Although no exploits have been reported in the wild yet, the ease of exploitation and critical impact make this a severe threat. The vulnerability affects organizations using enaio’s AppConnector component, which is commonly deployed in enterprise environments for document and workflow management. Attackers could leverage this flaw to send phishing emails, spam, or malicious payloads from trusted infrastructure, damaging organizational reputation and causing operational disruptions.

For European organizations, the impact of CVE-2025-56425 is significant due to the widespread use of enaio in enterprise document management, particularly in sectors like manufacturing, finance, and public administration. Exploitation could lead to unauthorized email transmissions that may facilitate phishing campaigns, data exfiltration, or spreading malware internally and externally. The high confidentiality impact means sensitive documents or communications could be exposed. The availability impact could disrupt email services, affecting business continuity. Organizations with exposed or insufficiently protected API endpoints are at higher risk. The reputational damage and potential regulatory consequences under GDPR for data breaches further amplify the impact. Additionally, the ability to send arbitrary SMTP commands could allow attackers to bypass email security controls, complicating detection and response efforts. This threat could also be leveraged as a pivot point for broader network compromise.

1. Apply patches or updates from the vendor as soon as they become available to address the vulnerability in the AppConnector component. 2. Until patches are released, restrict access to the /osrest/api/organization/sendmail endpoint by implementing network segmentation and firewall rules limiting access to trusted internal systems only. 3. Employ strict input validation and sanitization on all API inputs, especially those interacting with SMTP or command interfaces. 4. Monitor SMTP traffic for unusual patterns or unauthorized command sequences indicative of exploitation attempts. 5. Implement anomaly detection on email sending behavior to identify potential abuse of the SMTP relay. 6. Conduct regular security assessments and penetration testing focused on API endpoints and email infrastructure. 7. Educate IT and security teams about this vulnerability to ensure rapid detection and response. 8. Review and tighten email server configurations to prevent unauthorized relay and enforce strong authentication mechanisms. 9. Maintain comprehensive logging and alerting on API usage and email sending activities to facilitate forensic analysis if exploitation occurs.