CVE-2025-11290 is a medium-severity vulnerability affecting CRMEB versions up to 5.6.1, specifically within the JWT HMAC Secret Handler component. The vulnerability arises from the use of a hard-coded cryptographic key when the secret argument is manipulated with the input 'default'. This means that instead of using a unique, securely generated secret key for signing JSON Web Tokens (JWTs), the system falls back to a static, hard-coded key embedded in the software. Such a practice significantly weakens the cryptographic strength of JWTs, potentially allowing attackers to forge or tamper with tokens. The vulnerability can be exploited remotely without authentication or user interaction, but the attack complexity is considered high, making exploitation difficult. The CVSS 4.0 vector indicates network attack vector, high attack complexity, no privileges required, no user interaction, and low impact on confidentiality, integrity, and availability. The vendor has not responded to the disclosure, and no patches are currently available. Public exploit code exists, increasing the risk of exploitation despite the complexity. The vulnerability primarily compromises the integrity and confidentiality of JWT-based authentication or authorization mechanisms within CRMEB, potentially allowing unauthorized access or privilege escalation if exploited.

For European organizations using CRMEB versions 5.6.0 or 5.6.1, this vulnerability poses a risk to the security of their authentication and session management processes. Since JWTs are commonly used for stateless authentication, the use of a hard-coded key could allow attackers to forge tokens, impersonate users, or escalate privileges, leading to unauthorized access to sensitive data or administrative functions. This can result in data breaches, loss of customer trust, and regulatory non-compliance, especially under GDPR requirements for protecting personal data. The medium severity and high complexity of exploitation mean that while attacks are not trivial, motivated threat actors with sufficient resources could exploit this vulnerability, particularly in high-value targets such as e-commerce platforms, customer management systems, or SaaS providers using CRMEB. The lack of vendor response and absence of patches increase the window of exposure. Additionally, the public availability of exploit code lowers the barrier for attackers to attempt exploitation.

European organizations should immediately audit their CRMEB deployments to identify if versions 5.6.0 or 5.6.1 are in use. If so, they should consider the following specific mitigations: 1) Temporarily disable JWT-based authentication or replace it with alternative mechanisms until a patch or update is available. 2) Implement compensating controls such as network segmentation and strict access controls to limit exposure of vulnerable CRMEB instances. 3) Monitor logs for suspicious JWT token usage or anomalies indicative of token forgery attempts. 4) If possible, manually override or reconfigure the JWT secret key in the application configuration to avoid using the hard-coded default key, ensuring a strong, unique secret is used. 5) Engage with CRMEB vendor or community to seek updates or patches addressing this vulnerability. 6) Employ Web Application Firewalls (WAFs) with custom rules to detect and block exploitation attempts targeting JWT tokens. 7) Conduct penetration testing focused on JWT authentication flows to identify potential exploitation. These steps go beyond generic advice by focusing on immediate risk reduction and detection until an official patch is released.