CVE-2025-4613 is a high-severity vulnerability identified in Google Web Designer App versions prior to 16.3.0.0407 on Windows platforms. The root cause is improper input validation (CWE-20) related to the application's handling of ad templates. Specifically, the vulnerability is a path traversal flaw that allows an attacker to manipulate the file path input when loading or processing ad templates. By exploiting this flaw, an attacker can trick a user into downloading and opening a maliciously crafted ad template file. When the vulnerable application processes this template, the attacker can achieve remote code execution (RCE) on the victim's machine. This means arbitrary code can be executed with the privileges of the user running the application, potentially leading to full system compromise. The CVSS 4.0 base score is 7.1, indicating a high severity level. The vector string shows that the attack requires network access (AV:N), high attack complexity (AC:H), partial attack prerequisites (AT:P), low privileges (PR:L), and user interaction (UI:A). The vulnerability impacts confidentiality, integrity, and availability with varying degrees, and the scope is limited to the vulnerable application but can lead to system-level impact. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability is specific to Windows versions of Google Web Designer App, which is a tool used primarily for creating interactive HTML5-based designs and ads. The flaw arises from insufficient sanitization of input paths, allowing directory traversal sequences to access or overwrite unintended files during template handling, ultimately enabling code execution.

For European organizations, the impact of CVE-2025-4613 can be significant, especially for those involved in digital marketing, advertising, and web design where Google Web Designer is used. Successful exploitation can lead to remote code execution on workstations, potentially allowing attackers to install malware, steal sensitive data, or move laterally within corporate networks. This can disrupt business operations, compromise intellectual property, and lead to regulatory non-compliance under GDPR if personal data is exposed. The requirement for user interaction (opening a malicious template) means social engineering or phishing campaigns could be used to deliver the payload. Given the widespread use of Google products in Europe, organizations with marketing departments or agencies using this tool are at risk. The vulnerability’s exploitation could also serve as an initial foothold for more extensive attacks targeting critical infrastructure or government entities that use Google Web Designer for public communications or campaigns. The high attack complexity somewhat limits mass exploitation but targeted attacks against high-value organizations remain a concern.

1. Immediate mitigation should include restricting the use of Google Web Designer App to trusted users and environments until a patch is released. 2. Implement strict email and file attachment filtering to detect and block suspicious ad template files, especially those originating from untrusted sources. 3. Educate users on the risks of opening unsolicited or unexpected ad templates, emphasizing verification of file sources. 4. Employ endpoint detection and response (EDR) solutions to monitor for unusual file system activity or process execution related to Google Web Designer. 5. Use application whitelisting to prevent unauthorized execution of code spawned by the application. 6. Network segmentation can limit lateral movement if an endpoint is compromised. 7. Once available, promptly apply official patches or updates from Google. 8. Conduct regular audits of installed software versions across the organization to identify and remediate vulnerable instances. 9. Consider deploying sandbox environments for opening and testing ad templates before use in production. These steps go beyond generic advice by focusing on controlling the attack vector (malicious templates), user behavior, and monitoring specific to this vulnerability.