The mrdenny Time Sheets plugin for WordPress suffers from a Cross-Site Request Forgery (CSRF) vulnerability identified as CVE-2025-10055. This vulnerability exists in all versions up to and including 2.1.3 due to missing or incorrect nonce validation on several plugin endpoints. Nonces are security tokens used to verify that requests originate from legitimate users and not from malicious third-party sites. Without proper nonce validation, attackers can craft malicious requests that, when executed by an authenticated administrator (via clicking a link or visiting a malicious page), perform unauthorized actions within the plugin. These actions could include modifying time sheet entries or other administrative functions exposed by the plugin. The vulnerability does not allow direct compromise of confidentiality or availability but impacts data integrity. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N) indicates network attack vector, low attack complexity, no privileges required, but user interaction is necessary. No patches are currently linked, and no known exploits have been observed in the wild, but the risk remains significant for sites with administrative users who might be targeted via social engineering. The vulnerability highlights the importance of nonce validation in WordPress plugin development to prevent CSRF attacks.

The primary impact of this vulnerability is the potential unauthorized modification of data managed by the Time Sheets plugin, which could disrupt business operations relying on accurate time tracking and reporting. Attackers can exploit this flaw to alter time sheet entries or other administrative settings without authentication, provided they can trick an administrator into performing an action. This undermines data integrity and could lead to inaccurate payroll, billing errors, or compliance issues. While the vulnerability does not compromise system confidentiality or availability directly, the integrity loss can have cascading operational and financial consequences. Organizations with multiple administrators or those that rely heavily on this plugin for workforce management are at higher risk. Additionally, the need for user interaction and targeting of privileged users limits the attack scope but does not eliminate the threat, especially in environments where phishing or social engineering is prevalent.

Organizations should immediately monitor for updates or patches from the mrdenny plugin developers and apply them as soon as they become available. In the interim, administrators should minimize exposure by limiting the number of users with administrative privileges and enforcing strict access controls. Employing web application firewalls (WAFs) with custom rules to detect and block suspicious CSRF attempts targeting the plugin endpoints can reduce risk. Educating administrators about phishing and social engineering tactics is critical to prevent inadvertent execution of malicious requests. Additionally, site owners can implement security plugins that enforce nonce validation or add additional CSRF protections at the WordPress level. Regular security audits and monitoring of plugin activity logs can help detect anomalous changes indicative of exploitation attempts. Finally, consider disabling or replacing the Time Sheets plugin with alternatives that follow secure coding practices if immediate patching is not feasible.