CVE-2025-64273 is a missing authorization vulnerability identified in the GetResponse Email marketing plugin for WordPress, maintained by GetResponse Official. The flaw exists in versions up to and including 1.5.3 and stems from incorrectly configured access control security levels, allowing unauthenticated remote attackers to perform unauthorized actions. Specifically, the vulnerability enables attackers to bypass authorization checks when interacting with certain plugin functionalities, leading to unauthorized modification of data within the plugin's scope. The CVSS v3.1 base score is 7.5, reflecting a high severity due to the vulnerability's network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The impact is primarily on integrity (I:H), with no direct confidentiality (C:N) or availability (A:N) impact. This means attackers can alter data managed by the plugin, potentially manipulating marketing campaigns, subscriber lists, or other critical email marketing configurations without detection. The vulnerability was reserved on 2025-10-29 and published on 2025-12-18. No known exploits have been reported in the wild, and no official patches have been linked yet. The plugin is widely used by WordPress sites for integrating GetResponse email marketing services, making this a significant risk vector for websites relying on this integration. The lack of authorization checks indicates a fundamental security design flaw in the plugin's access control mechanisms.

For European organizations, this vulnerability poses a significant risk to the integrity of their email marketing data and operations. Attackers exploiting this flaw could alter marketing campaigns, subscriber information, or email content, potentially leading to misinformation, reputational damage, and loss of customer trust. Since the plugin integrates directly with WordPress, a platform widely used across Europe, the attack surface is substantial. Unauthorized modifications could also facilitate further attacks, such as phishing campaigns or spreading malware via compromised email content. While confidentiality and availability are not directly impacted, the integrity compromise alone can disrupt business operations and marketing effectiveness. Organizations in sectors heavily reliant on digital marketing, such as retail, finance, and media, may experience amplified consequences. Additionally, regulatory compliance risks arise if altered marketing communications violate GDPR or other data protection laws due to unauthorized data manipulation.

1. Monitor GetResponse Official announcements and apply security patches immediately once available to remediate the missing authorization flaw. 2. Until patches are released, restrict access to WordPress admin and plugin-specific endpoints using IP whitelisting, VPNs, or web application firewalls (WAFs) to limit exposure to trusted users only. 3. Implement strict role-based access controls within WordPress to minimize the number of users with permissions to manage the GetResponse plugin. 4. Conduct regular audits of marketing campaign data and subscriber lists to detect unauthorized changes promptly. 5. Employ intrusion detection systems (IDS) and security monitoring tools to identify anomalous activities related to the plugin. 6. Consider temporarily disabling the GetResponse plugin if the risk outweighs operational necessity until a secure version is available. 7. Educate staff responsible for WordPress and marketing platforms about this vulnerability and encourage vigilance for suspicious behavior or unexpected changes. 8. Review and harden overall WordPress security posture, including keeping WordPress core and other plugins up to date, to reduce the attack surface.