CVE-2025-42909 identifies a vulnerability in SAP Cloud Appliance Library (CAL) Appliances, specifically in the TITANIUM_WEBAPP 4.0 version. The issue stems from an insecure default profile setting in S/4HANA appliances deployed via SAP CAL, where a sensitive cookie is set without the HttpOnly flag (CWE-1004). The HttpOnly attribute prevents client-side scripts from accessing cookies, mitigating risks such as cross-site scripting (XSS) attacks that could steal session cookies. In this case, the absence of HttpOnly means that an attacker with high privileges on one appliance could potentially access cookies that allow lateral movement or unauthorized access to other SAP CAL appliances within the same environment. The vulnerability requires the attacker to have high privileges on an existing appliance, limiting the attack surface. The CVSS v3.1 score is 3.0 (low severity), reflecting low confidentiality impact and no integrity or availability impact. The attack vector is network-based, with high attack complexity and no user interaction needed. No public exploits have been reported, and no patches are currently linked, indicating that mitigation may rely on configuration changes or upcoming vendor updates. The vulnerability highlights the importance of secure default configurations in enterprise cloud appliance deployments, especially in environments where multiple SAP CAL appliances coexist and share trust boundaries.

For European organizations, the primary impact is a low-level confidentiality risk where an attacker with already high privileges on one SAP CAL appliance could access sensitive cookies and potentially move laterally to other appliances. Although integrity and availability are not affected, unauthorized access to multiple appliances could lead to broader exposure of sensitive business data or configurations. Organizations using SAP S/4HANA via SAP CAL in multi-appliance deployments are at risk, particularly if they rely on default profile settings without additional hardening. The vulnerability could facilitate insider threats or compromise escalation scenarios. Given SAP's widespread use in European enterprises, especially in manufacturing, finance, and public sectors, even low-severity vulnerabilities warrant attention to prevent chained attacks. The lack of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation.

European organizations should immediately audit their SAP CAL appliance configurations, focusing on the S/4HANA default profile settings related to cookie security. Specifically, ensure that all sensitive cookies have the HttpOnly flag set to prevent client-side script access. Where possible, apply custom profile parameters or security patches from SAP once available. Limit high-privilege access strictly to trusted administrators and monitor for unusual lateral movement between appliances. Implement network segmentation to isolate SAP CAL appliances and reduce the risk of cross-appliance compromise. Regularly review SAP security notes and advisories for updates on this vulnerability. Employ web application firewalls (WAFs) to detect and block suspicious cookie-related activities. Finally, conduct internal penetration testing to verify that cookie attributes are correctly configured and that no unauthorized access paths exist between appliances.