CVE-2024-0866 in Check & Log Email Plugin
Summary
by MITRE • 03/26/2024
The Check & Log Email plugin for WordPress is vulnerable to Unauthenticated Hook Injection in all versions up to, and including, 1.0.9 via the check_nonce function. This makes it possible for unauthenticated attackers to execute actions with hooks in WordPress under certain circumstances. The action the attacker wishes to execute needs to have a nonce check, and the nonce needs to be known to the attacker. Furthermore, the absence of a capability check is a requirement.
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Analysis
by VulDB Data Team • 04/13/2026
The Check & Log Email plugin for WordPress presents a critical security vulnerability classified as CVE-2024-0866, affecting all versions up to and including 1.0.9. This vulnerability stems from an improper implementation of the check_nonce function which creates an exploitable condition for unauthenticated attackers. The flaw allows malicious actors to inject hooks into WordPress execution flow without proper authentication, representing a significant breach in the platform's security model. The vulnerability operates through a specific attack vector that requires the attacker to possess knowledge of a valid nonce value and to target actions that are protected by nonce validation mechanisms. This creates a scenario where the attacker can manipulate WordPress hook execution without being authenticated to the system, potentially leading to unauthorized actions within the WordPress environment.
The technical exploitation of this vulnerability occurs through a fundamental flaw in the plugin's nonce handling mechanism. When WordPress processes hooks that require nonce validation, the check_nonce function fails to properly validate the authenticity of the nonce or to enforce proper capability checks. This creates an opportunity for attackers to craft malicious requests that bypass normal authentication requirements. The vulnerability specifically targets WordPress hooks that are designed to execute with specific permissions or capabilities, but due to the missing capability validation, these hooks can be triggered by unauthenticated users. The absence of proper access controls combined with predictable nonce handling creates a dangerous condition where attackers can execute arbitrary actions within the WordPress system. This type of vulnerability is categorized under CWE-347, which deals with improper verification of cryptographic signatures or tokens, and aligns with ATT&CK technique T1078.004 for Valid Accounts and T1566.002 for Phishing with Spoofed Credentials.
The operational impact of this vulnerability extends beyond simple unauthorized access, potentially allowing attackers to perform administrative actions within the WordPress environment. Since the vulnerability requires the attacker to know a valid nonce, it suggests that the plugin may be generating nonces that are either predictable or exposed through other means within the application's behavior. The requirement for a nonce check to be present on the target action means that attackers must identify specific WordPress actions that are vulnerable to this manipulation. This limitation reduces the scope of exploitable actions but does not eliminate the risk entirely, as many WordPress administrative functions may be susceptible to similar nonce handling issues. The vulnerability creates a pathway for attackers to execute hooks that should normally require elevated privileges, potentially enabling them to modify plugin settings, access sensitive data, or even install malicious code. The lack of capability checks means that even if an attacker cannot directly execute administrative commands, they can still manipulate WordPress hooks that may have unintended consequences when executed with default permissions.
Mitigation strategies for CVE-2024-0866 should focus on immediate plugin updates to versions that address the nonce handling implementation. System administrators must ensure that all instances of the Check & Log Email plugin are updated to versions that properly validate nonces and enforce capability checks. Organizations should implement network monitoring to detect unusual hook execution patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and authentication mechanisms in WordPress plugins, particularly those that interact with core WordPress functionality. Security teams should conduct comprehensive audits of all installed plugins to identify similar nonce handling issues. Additionally, implementing web application firewalls and rate limiting mechanisms can help detect and prevent exploitation attempts. The vulnerability serves as a reminder of the critical importance of validating all user inputs and ensuring that WordPress hooks are properly secured against unauthorized access. Organizations should also consider implementing security headers and additional authentication layers to reduce the attack surface for such vulnerabilities. Regular security assessments and penetration testing should include verification of nonce handling in all WordPress plugins to prevent similar issues from being overlooked in the future.