CVE-2016-11011 in wp-invoice Plugin
Summary
by MITRE
The wp-invoice plugin before 4.1.1 for WordPress has wpi_update_user_option privilege escalation.
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Analysis
by VulDB Data Team • 12/26/2023
The wp-invoice plugin for WordPress contains a critical privilege escalation vulnerability that affects versions prior to 4.1.1. This vulnerability resides in the wpi_update_user_option function which fails to properly validate user permissions before executing administrative operations. The flaw allows authenticated attackers with lower privileges to escalate their access level and perform actions typically restricted to administrators or privileged users within the WordPress environment. The vulnerability specifically targets the plugin's user option update mechanism, where insufficient input validation and access control checks enable malicious actors to manipulate user permissions and gain unauthorized administrative capabilities.
The technical implementation of this vulnerability stems from improper authorization checks within the plugin's core functionality. When the wpi_update_user_option function processes user requests, it does not verify whether the requesting user possesses sufficient privileges to modify the target user's options. This creates a direct path for privilege escalation where attackers can manipulate the function parameters to update user roles and capabilities without proper authentication. The vulnerability operates at the application layer and specifically affects WordPress installations that utilize the wp-invoice plugin, making it particularly dangerous in multi-user environments where various user roles exist. According to CWE classification, this represents a weakness in authorization mechanisms where proper access control checks are missing or improperly implemented, specifically categorized under CWE-284 for improper access control.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can lead to complete system compromise when combined with other attack vectors. An attacker who gains access to a user account with limited privileges can exploit this vulnerability to elevate their permissions and subsequently access sensitive data, modify content, install malicious plugins, or even execute arbitrary code on the WordPress server. The vulnerability is particularly concerning because it operates silently without requiring additional authentication mechanisms, making detection difficult for system administrators. Attackers can leverage this weakness to establish persistent access to the WordPress installation, potentially using it as a foothold for further attacks within the network infrastructure. This vulnerability aligns with ATT&CK technique T1078 for valid accounts and T1484 for domain policy modification, as it enables attackers to manipulate user permissions and establish unauthorized access to administrative functions.
Mitigation strategies for this vulnerability require immediate plugin updates to version 4.1.1 or later, where the privilege escalation issue has been addressed through proper access control implementation. System administrators should also implement comprehensive monitoring of user activity within the wp-invoice plugin, particularly focusing on unusual user option modifications that could indicate exploitation attempts. Additional defensive measures include restricting plugin access through web application firewalls, implementing role-based access controls, and conducting regular security audits of installed WordPress plugins to identify similar vulnerabilities. The remediation process should also involve reviewing and hardening WordPress user permissions, ensuring that only authorized personnel maintain administrative privileges. Organizations should consider implementing automated patch management systems to ensure timely updates of all WordPress components, as this vulnerability demonstrates how outdated plugins can create significant security risks within WordPress environments. Security teams should also perform penetration testing to identify other potential privilege escalation paths within their WordPress installations and implement proper input validation and access control measures across all custom plugin functions.