CVE-2025-4894 is a vulnerability identified in the calmkart Django-sso-server, specifically affecting the gen_rsa_keys function within the common/crypto.py file. This function is responsible for generating RSA encryption keys used in the single sign-on (SSO) server. The vulnerability results in inadequate encryption strength, meaning the cryptographic keys generated do not meet recommended security standards, potentially making them susceptible to cryptanalysis or brute-force attacks. The vulnerability can be exploited remotely without requiring authentication or user interaction, but the attack complexity is high and exploitation is difficult. The product uses a rolling release model, so specific version numbers for affected or patched releases are not available. The CVSS 4.0 base score is 6.3 (medium severity), reflecting a network attack vector with high complexity, no privileges or user interaction needed, and limited impact on confidentiality. The vulnerability does not affect integrity or availability directly. No known exploits are currently in the wild, and no patches have been publicly linked yet. This vulnerability could allow attackers to weaken the cryptographic protections of the SSO server, potentially enabling interception or decryption of sensitive authentication tokens or session data if combined with other attack vectors.

For European organizations relying on calmkart Django-sso-server for authentication and identity management, this vulnerability poses a risk to the confidentiality of authentication credentials and session tokens. If exploited, attackers could potentially decrypt or compromise SSO tokens, leading to unauthorized access to multiple connected services. This could result in data breaches, unauthorized data access, and lateral movement within enterprise networks. Given the high complexity and difficulty of exploitation, the immediate risk is moderate, but organizations with high-value or sensitive data, especially in sectors like finance, healthcare, and government, could face significant consequences if attackers develop reliable exploit methods. The rolling release nature complicates patch management, increasing the risk of unpatched systems in production. Additionally, the vulnerability could undermine trust in SSO implementations, which are critical for streamlined and secure user authentication across many European enterprises.

1. Conduct a thorough audit of the calmkart Django-sso-server deployment to identify affected instances. 2. Engage with the calmkart project or vendor to obtain updates or patches addressing the gen_rsa_keys function and ensure cryptographic key generation meets current security standards (e.g., minimum 2048-bit RSA keys). 3. If patches are unavailable, consider temporarily disabling or restricting remote access to the SSO server to trusted networks only. 4. Implement additional layers of security such as multi-factor authentication (MFA) to reduce reliance on the compromised encryption strength. 5. Monitor network traffic and authentication logs for unusual activity that could indicate attempts to exploit weak encryption. 6. Plan for a migration or upgrade strategy to a more secure SSO solution if calmkart does not provide timely remediation. 7. Educate security teams about the risks of cryptographic weaknesses and incorporate cryptographic best practices into development and deployment pipelines. 8. Use cryptographic libraries and key generation methods that comply with recognized standards (e.g., NIST recommendations) and avoid custom or weak implementations.