CVE-2025-48960 is a security vulnerability identified in Acronis Cyber Protect 16, a widely used backup and cybersecurity solution available on Linux, macOS, and Windows platforms. The vulnerability is categorized under CWE-326, which pertains to the use of weak cryptographic keys. Specifically, this issue involves the use of a weak server key for TLS encryption within the product versions prior to build 39938. TLS (Transport Layer Security) is critical for securing communications between clients and servers, ensuring confidentiality and integrity of data in transit. A weak server key undermines the strength of the TLS encryption, potentially allowing attackers to decrypt, intercept, or manipulate data exchanged during these sessions. The CVSS v3.0 base score assigned to this vulnerability is 5.9, indicating a medium severity level. The vector string (AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N) reveals that the attack vector is adjacent network (AV:A), requiring high attack complexity (AC:H), no privileges (PR:N), no user interaction (UI:N), unchanged scope (S:U), low confidentiality impact (C:L), high integrity impact (I:H), and no availability impact (A:N). This suggests that while exploitation is somewhat difficult due to the high attack complexity and adjacency requirement, a successful attack could lead to significant integrity compromise, such as unauthorized modification of data or commands within the protected environment. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that remediation may still be pending or in progress. The vulnerability affects all platforms supported by Acronis Cyber Protect 16, which is a critical tool for enterprise backup, disaster recovery, and cybersecurity management.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on Acronis Cyber Protect 16 for backup and cybersecurity operations. The use of weak TLS keys could allow attackers positioned within the same network segment (e.g., internal networks, VPNs, or local area networks) to intercept or manipulate sensitive backup data or management commands. This could lead to unauthorized data tampering, undermining the integrity of backups and potentially causing data loss or corruption during recovery processes. Given the critical nature of backup data in business continuity and disaster recovery, such integrity compromises could disrupt operations, cause regulatory compliance issues (especially under GDPR), and damage organizational reputation. Additionally, since the vulnerability does not require user interaction or privileges, it could be exploited by insiders or lateral movement attackers within a compromised network. The medium CVSS score reflects the balance between exploitation difficulty and potential impact, but the high integrity impact is particularly concerning for organizations that depend on data accuracy and trustworthiness. The absence of known exploits suggests a window of opportunity for organizations to proactively address the issue before active exploitation occurs.

Organizations should prioritize upgrading Acronis Cyber Protect 16 to build 39938 or later once the vendor releases a patch addressing this vulnerability. Until a patch is available, network segmentation should be enforced to limit access to the Acronis management interfaces and backup servers to trusted hosts only, reducing the risk of adjacent network attackers. Employing strict access controls, including network-level authentication and firewall rules, can help prevent unauthorized lateral movement. Monitoring network traffic for unusual TLS handshake anomalies or unexpected certificate/key usage may provide early detection of exploitation attempts. Additionally, organizations should review and strengthen their cryptographic policies and configurations, ensuring that only strong, industry-standard cryptographic algorithms and key lengths are used across all systems. Conducting regular vulnerability assessments and penetration tests focusing on backup infrastructure can help identify weaknesses. Finally, maintaining comprehensive incident response plans that include backup integrity verification procedures will aid in rapid detection and recovery if exploitation occurs.