CVE-2025-67961 is a Server-Side Request Forgery (SSRF) vulnerability identified in the WPO365 plugin developed by Marco van Wieren, which facilitates integration between WordPress sites and Microsoft 365 services. The vulnerability affects all versions up to and including 40.0. SSRF vulnerabilities occur when an attacker can manipulate a server to send crafted HTTP requests to arbitrary destinations, often internal network resources that are otherwise inaccessible externally. In this case, the vulnerability requires an authenticated user with low privileges (PR:L) but no user interaction (UI:N), and the attack vector is network-based (AV:N). The vulnerability has a CVSS 3.1 base score of 6.4, indicating a medium severity level. The impact includes limited confidentiality and integrity loss, as the attacker may access internal services or sensitive data by forcing the server to make unauthorized requests. The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. There are no known exploits in the wild currently, and no patches have been linked yet. The vulnerability could be exploited to perform internal network reconnaissance, access metadata services, or interact with internal APIs, potentially leading to further compromise or data leakage. The lack of user interaction lowers the barrier for exploitation once the attacker has valid credentials. The vulnerability is particularly relevant for organizations using WPO365 for Office 365 login and integration on WordPress sites, which are common in enterprise environments.

For European organizations, this SSRF vulnerability poses a risk primarily to the confidentiality and integrity of internal network resources. Attackers with low-level authenticated access could leverage the vulnerability to probe internal services, access sensitive information, or manipulate internal APIs that are not exposed externally. This could lead to unauthorized data disclosure, including potentially sensitive corporate or user data. The integrity impact, while limited, could involve manipulation of internal service responses or triggering unintended actions within internal systems. Availability impact is minimal as the vulnerability does not directly enable denial of service. Organizations relying on WPO365 for Microsoft 365 integration in WordPress environments may face increased risk of lateral movement or escalation if internal services are exposed via SSRF. Given the medium severity and requirement for authentication, the threat is significant but manageable with proper controls. The absence of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation. European entities handling sensitive data or critical infrastructure should prioritize addressing this vulnerability to prevent potential exploitation that could lead to data breaches or compliance violations under GDPR.

1. Monitor for and apply official patches or updates from Marco van Wieren as soon as they become available to remediate the SSRF vulnerability. 2. Implement strict input validation and sanitization on all parameters that can influence server-side requests to prevent malicious URL injection. 3. Restrict outbound HTTP requests from the WordPress server to only trusted and necessary endpoints using firewall rules or network segmentation to limit SSRF attack surface. 4. Enforce the principle of least privilege for user accounts, ensuring that only trusted users have access to the WPO365 plugin features requiring authentication. 5. Employ Web Application Firewalls (WAF) with SSRF detection capabilities to identify and block suspicious request patterns. 6. Conduct regular security audits and penetration testing focusing on SSRF and related vulnerabilities in WordPress plugins. 7. Monitor logs for unusual outbound requests or access patterns that could indicate exploitation attempts. 8. Educate administrators and developers about SSRF risks and secure coding practices related to server-side HTTP requests. 9. Consider isolating the WordPress environment hosting WPO365 from sensitive internal networks to reduce potential impact. 10. Review and update incident response plans to include SSRF attack scenarios for timely detection and mitigation.