CVE-2025-22535 identifies a critical SQL Injection vulnerability in the jonkern WPListCal WordPress plugin, specifically affecting versions up to and including 1.3.5. The vulnerability arises from improper neutralization of special characters in SQL commands, allowing attackers to manipulate backend database queries. This can enable unauthorized retrieval, modification, or deletion of sensitive data stored in the WordPress database. The flaw is present in the plugin's handling of user-supplied input that is incorporated into SQL statements without adequate sanitization or parameterization. Since WordPress plugins often run with database privileges, successful exploitation can compromise the confidentiality and integrity of website data. No CVSS score has been assigned yet, and no patches or official fixes have been published as of the vulnerability disclosure date. There are no known active exploits in the wild, but the vulnerability's nature and ease of exploitation without authentication make it a significant threat. The affected plugin is used primarily in WordPress environments, which are widely deployed globally, especially in small to medium business websites. Attackers could leverage this vulnerability to extract sensitive information such as user credentials, content, or configuration data, or even escalate privileges within the compromised site.

The impact of this SQL Injection vulnerability is potentially severe for organizations using the WPListCal plugin. Attackers could gain unauthorized access to sensitive data stored in the WordPress database, including user information, content, and possibly administrative credentials. This could lead to data breaches, defacement, or further compromise of the hosting environment. The integrity of website data could be undermined, and availability might be affected if attackers execute destructive SQL commands. Since the vulnerability does not require authentication, any attacker with network access to the vulnerable site could attempt exploitation, increasing the attack surface. Organizations relying on WPListCal for calendar functionality may face operational disruptions if the plugin is disabled or compromised. The absence of patches means organizations must rely on interim mitigations, increasing risk exposure. The reputational damage and regulatory consequences of a data breach stemming from this vulnerability could be significant, especially for entities handling sensitive or personal data.

To mitigate the risk posed by CVE-2025-22535, organizations should immediately assess their WordPress installations for the presence of the WPListCal plugin and determine the version in use. If the plugin is present and running version 1.3.5 or earlier, it is advisable to disable or uninstall the plugin until a security patch is released. Monitor official channels from the vendor or trusted security advisories for updates or patches addressing this vulnerability. In the interim, implement Web Application Firewall (WAF) rules to detect and block SQL Injection attempts targeting the plugin’s endpoints. Employ input validation and sanitization at the application level where possible. Conduct thorough security audits and database access monitoring to detect any suspicious activity. Regularly back up website data and databases to enable recovery in case of compromise. Additionally, consider restricting access to administrative interfaces and sensitive endpoints through IP whitelisting or VPNs to reduce exposure. Educate site administrators about the risks and signs of exploitation to enable rapid response.