CVE-2025-40603 identifies a vulnerability in SonicWall SMA100 Series appliances, specifically versions 10.2.2.2-92sv and earlier, where sensitive information such as partial user credentials is inadvertently recorded in log files. This vulnerability falls under CWE-532, which concerns the insertion of sensitive data into logs, potentially exposing it to unauthorized parties. The threat actor must be a remote, authenticated administrator to exploit this vulnerability, implying that some level of access is required before the vulnerability can be leveraged. Under certain conditions, these administrators can view partial credential data of users by accessing the logs, which could lead to further compromise if the credentials are used to escalate privileges or access other systems. Although no known exploits are currently active in the wild, the presence of sensitive credential data in logs represents a significant confidentiality risk. The vulnerability does not have a CVSS score assigned yet, but the nature of the exposure and the requirement for authentication suggest a high severity. The SonicWall SMA100 appliances are widely deployed in enterprise environments for secure remote access and VPN services, making this vulnerability particularly relevant for organizations relying on these devices for secure communications. The lack of a patch at the time of publication necessitates immediate mitigation steps to prevent potential exploitation.

For European organizations, the exposure of partial user credential data in SonicWall SMA100 logs can lead to significant confidentiality breaches. Attackers or malicious insiders with authenticated access could leverage this information to escalate privileges, impersonate users, or gain unauthorized access to sensitive systems. This could compromise the integrity of secure remote access infrastructure, potentially leading to lateral movement within networks and data exfiltration. Given the critical role of SMA100 appliances in securing VPN and remote access, exploitation could disrupt business continuity and expose sensitive corporate or personal data. The impact is heightened in sectors with stringent data protection requirements such as finance, healthcare, and government institutions across Europe. Additionally, the exposure of credentials could conflict with GDPR mandates on data protection and breach notification, increasing legal and compliance risks for affected organizations.

European organizations using SonicWall SMA100 appliances should immediately restrict access to log files to only the most trusted and necessary administrators to minimize exposure. Implement strict role-based access controls (RBAC) and monitor administrative activities for unusual access patterns. Regularly audit log files to identify and remove sensitive information where possible. Until an official patch is released by SonicWall, consider disabling or limiting logging features that capture sensitive credential data if feasible without compromising operational visibility. Employ network segmentation to isolate management interfaces of SMA100 appliances from broader network access. Additionally, enforce strong authentication mechanisms such as multi-factor authentication (MFA) for all administrative access to reduce the risk of credential compromise. Stay informed on vendor updates and apply patches promptly once they become available. Finally, conduct user awareness training to ensure administrators understand the sensitivity of log data and the importance of secure handling.