CVE-2024-55539 is a vulnerability identified in the Acronis Cyber Protect Cloud Agent for Linux systems, specifically affecting versions prior to build 39185 for the Cloud Agent and build 39938 for Acronis Cyber Protect 16. The core issue is the use of a weak cryptographic algorithm to sign RPM packages distributed by Acronis. This weakness falls under CWE-327, which pertains to the use of cryptographically weak algorithms that can undermine the integrity verification process. RPM package signing is critical for ensuring that software updates and installations are authentic and have not been tampered with. A weak signing algorithm could potentially allow an attacker with local access and some privileges to craft malicious RPM packages that appear legitimate, thereby bypassing integrity checks. However, exploitation requires local access with low privileges and high attack complexity, with no user interaction needed. The CVSS 3.0 base score is 2.5 (low severity), reflecting limited impact on confidentiality and availability, and only a partial impact on integrity. No known exploits are reported in the wild, and no patches have been linked yet, indicating this is a newly disclosed issue. The vulnerability is specific to Linux deployments of Acronis Cyber Protect Cloud Agent, a widely used backup and cybersecurity solution in enterprise environments.

For European organizations, the impact of this vulnerability is primarily related to the integrity of the Acronis Cyber Protect Cloud Agent software updates and installations on Linux systems. If exploited, attackers could potentially introduce malicious code or tampered updates that might evade detection by the agent, undermining the security posture of affected endpoints. This could lead to unauthorized modifications or persistence mechanisms within critical infrastructure or enterprise environments. However, given the requirement for local access and the high complexity of exploitation, the risk is somewhat mitigated in well-managed environments. Still, organizations relying heavily on Acronis Cyber Protect for endpoint protection and backup in Linux environments should consider this vulnerability seriously, as it could be leveraged as part of a multi-stage attack chain. The low CVSS score suggests limited immediate threat, but the potential for integrity compromise in security-critical software warrants proactive measures.

European organizations should prioritize upgrading affected Acronis Cyber Protect Cloud Agent versions to the fixed builds (build 39185 or later for the Cloud Agent and build 39938 or later for Acronis Cyber Protect 16) as soon as patches become available. Until patches are released, organizations should restrict local access to Linux systems running Acronis agents to trusted administrators only, enforce strict privilege management, and monitor for unusual package installation activities. Implementing additional integrity verification mechanisms, such as out-of-band verification of package signatures or using alternative trusted package repositories, can help mitigate risks. Regular auditing of installed packages and anomaly detection on endpoint systems can also provide early warning of tampering attempts. Network segmentation to isolate critical Linux systems and limiting software installation capabilities to authorized personnel will further reduce exploitation likelihood. Finally, organizations should maintain up-to-date threat intelligence feeds to detect any emerging exploit attempts targeting this vulnerability.