CVE-2025-57789 is a vulnerability identified in Commvault's CommCell software versions prior to 11.36.60. The flaw arises during the initial setup phase of the product, specifically in the brief window between installation and the first administrator login. During this period, the system uses a default credential that is stored in a recoverable format, which can be exploited by remote attackers to gain administrative control over the CommCell environment. This vulnerability is categorized under CWE-257, which pertains to storing passwords in a recoverable format, indicating that the credentials are not properly protected or hashed, allowing potential retrieval by unauthorized parties. The CVSS 4.0 base score is 5.3 (medium severity), reflecting that the attack vector is network-based with low attack complexity and no user interaction required. However, the attack requires low privileges (PR:L), meaning the attacker must have some limited access, possibly network access to the setup interface. The impact includes potential unauthorized administrative access, which could lead to compromise of backup data, manipulation of backup jobs, or disruption of data protection services. The vulnerability is limited to the setup phase before any jobs are configured, which narrows the exploitation window but still poses a significant risk if an attacker can access the system during this time. No known exploits are reported in the wild yet, and no patches have been linked at the time of this report.

For European organizations, the impact of this vulnerability can be significant, especially for enterprises relying on Commvault CommCell for critical data backup and recovery operations. Unauthorized administrative access during setup could allow attackers to manipulate backup configurations, potentially leading to data loss, data integrity issues, or ransomware scenarios where backups are corrupted or deleted. This could disrupt business continuity and compliance with data protection regulations such as GDPR. Since the vulnerability is exploitable remotely and does not require user interaction, attackers could target newly deployed or recently updated CommCell instances before administrators complete the initial login. This risk is heightened in environments where setup occurs on systems exposed to less secure networks or where initial deployment procedures do not restrict network access. The limited exploitation window reduces the likelihood of widespread attacks but does not eliminate the risk, especially in large organizations with frequent deployments or cloud-based setups.

To mitigate this vulnerability, organizations should implement the following specific measures: 1) Restrict network access to CommCell setup interfaces during installation by using network segmentation, firewalls, or VPNs to ensure only trusted administrators can reach the system. 2) Accelerate the initial administrator login process immediately after installation to minimize the exposure window where default credentials are active. 3) Monitor network traffic and logs for unauthorized access attempts during deployment phases. 4) Employ strict access control policies and multi-factor authentication for administrative accounts once setup is complete. 5) Follow vendor advisories closely and apply patches or updates as soon as they become available. 6) Consider deploying CommCell in isolated environments during setup to prevent remote exploitation. 7) Conduct security awareness training for administrators to emphasize the importance of securing the setup phase. These steps go beyond generic advice by focusing on securing the specific vulnerable window and controlling network exposure during installation.