CVE-2025-7821 is a security vulnerability identified in the WC Plus plugin for WordPress, affecting all versions up to and including 1.2.0. The vulnerability arises from a missing authorization check (CWE-862) on the AJAX action 'pluswc_logo_favicon_logo_base'. Specifically, the plugin fails to verify whether the requester has the necessary capabilities to perform this action, allowing unauthenticated attackers to modify the site's favicon logo base. This flaw enables attackers to update the favicon without any authentication or user interaction, which could be leveraged to conduct defacement, phishing, or social engineering attacks by replacing the favicon with malicious or misleading images. The vulnerability has a CVSS v3.1 base score of 5.3 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), low integrity impact (I:L), and no availability impact (A:N). There are no known exploits in the wild at the time of publication, and no official patches have been linked yet. The vulnerability was reserved in July 2025 and published in August 2025 by Wordfence. Given the nature of WordPress plugins and their widespread use, this vulnerability could be exploited remotely by attackers to alter site appearance and potentially undermine user trust or facilitate further attacks through visual deception.

For European organizations, especially those relying on WordPress for their web presence, this vulnerability poses a risk to website integrity and brand reputation. Unauthorized favicon modification can be used to display misleading or malicious icons, potentially tricking users into trusting fraudulent sites or facilitating phishing campaigns. Although the vulnerability does not directly compromise confidentiality or availability, the integrity impact can lead to reputational damage, loss of customer trust, and indirect financial losses. Organizations in sectors such as e-commerce, finance, government, and media, where website trustworthiness is critical, may face heightened risks. Additionally, given the ease of exploitation (no authentication or user interaction required), attackers could automate attacks at scale, affecting multiple sites. The absence of known exploits currently provides a window for mitigation, but the medium severity score indicates that timely patching or mitigation is important to prevent potential abuse.

European organizations using the WC Plus plugin should immediately audit their WordPress installations to identify affected versions (up to 1.2.0). Since no official patches are currently linked, temporary mitigations include disabling the vulnerable AJAX action 'pluswc_logo_favicon_logo_base' via custom code or security plugins that can block unauthorized AJAX requests. Implementing a Web Application Firewall (WAF) with rules to detect and block suspicious AJAX calls targeting this action can reduce exposure. Organizations should also monitor website favicon changes and maintain integrity checks on website assets to detect unauthorized modifications promptly. Updating to a patched version once available is critical. Additionally, restricting administrative access and enforcing least privilege principles on WordPress user roles can limit potential damage. Regular backups of website files and configurations will facilitate recovery if unauthorized changes occur. Finally, educating web administrators about this vulnerability and encouraging vigilance against phishing attempts leveraging favicon spoofing is recommended.