CVE-2025-40595 is a high-severity Server-Side Request Forgery (SSRF) vulnerability identified in the SonicWall SMA1000 Appliance, specifically affecting the Work Place interface. The vulnerability exists due to improper validation of URLs processed by the appliance, allowing a remote, unauthenticated attacker to craft encoded URLs that cause the appliance to send requests to arbitrary internal or external locations. This can lead to unauthorized internal network scanning, data exfiltration, or interaction with internal services that are otherwise inaccessible from the attacker’s location. The vulnerability affects SMA1000 versions 12.4.3-02925 (platform-hotfix) and earlier. The CVSS 3.1 base score is 7.2, reflecting a network attack vector with low attack complexity, no privileges or user interaction required, and a scope change, impacting confidentiality and integrity but not availability. The SSRF flaw can be exploited without authentication, increasing its risk profile. Although no known exploits are currently reported in the wild, the potential for attackers to leverage this vulnerability to pivot into internal networks or access sensitive data is significant. SonicWall has not yet published patches or mitigations at the time of this report, emphasizing the need for immediate attention from affected organizations.

For European organizations, the impact of this SSRF vulnerability in SonicWall SMA1000 appliances can be substantial. Many enterprises and government agencies use SonicWall products for secure remote access and network security. Exploitation could allow attackers to bypass perimeter defenses, access internal services, and potentially extract sensitive information or conduct reconnaissance within private networks. This is particularly critical for sectors handling sensitive personal data under GDPR, such as healthcare, finance, and public administration. The confidentiality and integrity of data could be compromised, leading to regulatory penalties, reputational damage, and operational disruptions. Since the vulnerability requires no authentication, attackers can attempt exploitation from outside the network, increasing the risk of widespread attacks if the appliance is exposed to the internet. The lack of availability impact reduces the likelihood of direct denial-of-service conditions, but the stealthy nature of SSRF attacks may delay detection and response.

European organizations should immediately assess their exposure to SonicWall SMA1000 appliances running affected versions. Until official patches are released, organizations should implement the following mitigations: 1) Restrict network access to the SMA1000 Work Place interface by limiting inbound connections to trusted IP addresses via firewall rules or VPNs. 2) Monitor and log all requests to the appliance for unusual or encoded URL patterns indicative of SSRF attempts. 3) Employ network segmentation to isolate the SMA1000 appliance from critical internal services to minimize lateral movement if exploited. 4) Disable or restrict any unnecessary features or services on the SMA1000 that process external URLs. 5) Keep abreast of SonicWall advisories and apply patches promptly once available. 6) Conduct internal penetration testing to identify potential SSRF exploitation paths and verify the effectiveness of mitigations. These steps go beyond generic advice by focusing on network-level controls, monitoring, and segmentation tailored to the appliance’s role and exposure.