CVE-2025-1488 identifies an Open Redirect vulnerability (CWE-601) in the WPO365 | MICROSOFT 365 GRAPH MAILER plugin for WordPress, present in all versions up to and including 3.2. The vulnerability stems from inadequate validation of the 'redirect_to' URL parameter, which is used to redirect users after certain actions. Because the plugin does not properly verify that the redirect URL is safe or belongs to a trusted domain, attackers can craft malicious URLs that appear legitimate but redirect victims to attacker-controlled or malicious websites. Exploitation does not require authentication but does require user interaction, such as clicking a crafted link. The plugin must be activated but not configured for the vulnerability to be exploitable, indicating that default or incomplete setups are at risk. The CVSS 3.1 base score is 4.7, reflecting a medium severity with network attack vector, high attack complexity, no privileges required, user interaction needed, and partial impact on confidentiality and integrity but no impact on availability. Although no known exploits are currently reported in the wild, the vulnerability could facilitate phishing, credential theft, or malware distribution by leveraging trusted domains to bypass user suspicion. The vulnerability affects WordPress sites using this plugin, which integrates Microsoft 365 Graph API for mailer functionality, making it relevant for organizations relying on Microsoft 365 services within WordPress environments. No official patches or updates are listed, so mitigation relies on configuration and input validation controls.

The primary impact of this vulnerability is the potential for phishing and social engineering attacks. Attackers can exploit the open redirect to send users to malicious websites that may harvest credentials, distribute malware, or conduct further attacks under the guise of a trusted domain. This undermines user trust and can lead to data compromise or account takeover if users are deceived. Since the vulnerability requires user interaction and the plugin to be active but unconfigured, the scope is limited to sites with this specific setup. However, given the widespread use of WordPress and Microsoft 365 integrations, many organizations worldwide could be affected. The vulnerability does not directly compromise system integrity or availability but can indirectly lead to broader security incidents through successful phishing campaigns. Organizations with public-facing WordPress sites using this plugin are at risk, especially those with less stringent configuration management. The lack of authentication requirement lowers the barrier for attackers, but the high attack complexity and need for user interaction reduce the likelihood of automated mass exploitation.

To mitigate this vulnerability, organizations should first ensure the WPO365 | MICROSOFT 365 GRAPH MAILER plugin is fully configured according to vendor recommendations, avoiding default or incomplete setups that leave the 'redirect_to' parameter unchecked. Implement strict validation and sanitization of all redirect URLs, allowing only trusted domains or relative paths to prevent redirection to untrusted sites. Employ web application firewalls (WAFs) with rules to detect and block suspicious redirect parameters. Educate users about the risks of clicking on unexpected links, especially those involving redirects. Monitor logs for unusual redirect patterns or spikes in traffic to unknown domains. If possible, disable or remove the plugin until a vendor patch is released. Stay updated with vendor advisories for official patches or updates addressing this issue. Additionally, consider implementing Content Security Policy (CSP) headers to restrict navigation to trusted domains and reduce the impact of open redirects.