CVE-2025-40809 is an out-of-bounds write vulnerability classified under CWE-787 affecting Siemens Solid Edge SE2024 and SE2025 CAD software versions prior to V224.0 Update 14 and V225.0 Update 6 respectively. The flaw arises when the software parses specially crafted PRT files, which are proprietary part files used in Solid Edge. An attacker who can convince a user to open or process a malicious PRT file can trigger an out-of-bounds write, leading to memory corruption. This memory corruption can cause the application to crash (denial of service) or, more critically, enable arbitrary code execution within the context of the current user process. The CVSS 3.1 base score is 7.8, reflecting high severity due to the potential for full compromise of the affected application. The attack vector is local (AV:L), requiring the attacker to have local access or deliver the malicious file to the user. No privileges are required (PR:N), but user interaction is necessary (UI:R) to open the malicious file. The vulnerability affects confidentiality, integrity, and availability (C:H/I:H/A:H), making it a significant risk. Siemens has not yet published patches at the time of this report, and no known exploits have been observed in the wild. The vulnerability was reserved in April 2025 and published in October 2025. This vulnerability is particularly concerning for organizations relying on Solid Edge for critical design and manufacturing workflows, as exploitation could lead to intellectual property theft, sabotage, or disruption of engineering processes.

For European organizations, especially those in manufacturing, automotive, aerospace, and engineering sectors that utilize Siemens Solid Edge software, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized code execution, allowing attackers to steal sensitive design data, manipulate CAD models, or disrupt production workflows. This could result in intellectual property loss, financial damage, and reputational harm. Additionally, denial of service through application crashes could interrupt critical design activities, delaying projects and increasing operational costs. Since Siemens Solid Edge is widely used in Europe, particularly in countries with strong industrial bases, the impact could be widespread. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, as attackers may use phishing or social engineering to deliver malicious files. The high confidentiality, integrity, and availability impact ratings underscore the potential for severe consequences if exploited.

1. Apply Siemens Solid Edge updates promptly once Siemens releases patches for the affected versions (V224.0 Update 14 and V225.0 Update 6 or later). 2. Until patches are available, restrict the opening of PRT files from untrusted or unknown sources. Implement strict file validation and scanning policies for CAD files entering the environment. 3. Educate users about the risks of opening unsolicited or suspicious PRT files, emphasizing caution with files received via email or external media. 4. Employ endpoint protection solutions capable of detecting anomalous behavior related to Solid Edge processes, including memory corruption attempts. 5. Use application whitelisting and sandboxing techniques to limit the impact of potential exploitation. 6. Monitor logs and network activity for unusual behavior originating from Solid Edge instances, such as unexpected process launches or network connections. 7. Implement strict access controls to limit local access to systems running Solid Edge to trusted personnel only. 8. Consider network segmentation to isolate engineering workstations from broader corporate networks to reduce lateral movement risk.