CVE-2023-6922 in Under Construction Maintenance Mode Plugin
Summary
by MITRE • 02/28/2024
The Under Construction / Maintenance Mode from Acurax plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 2.6 via the 'acx_csma_subscribe_ajax' function. This can allow authenticated attackers to extract sensitive data such as names and email addresses of subscribed visitors.
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Analysis
by VulDB Data Team • 02/07/2025
The vulnerability identified as CVE-2023-6922 affects the Acurax Under Construction / Maintenance Mode plugin for WordPress, specifically targeting versions up to and including 2.6. This security flaw resides within the 'acx_csma_subscribe_ajax' function which handles subscription requests for visitors who wish to receive notifications when a website comes out of maintenance mode. The plugin is commonly used by website administrators to display maintenance pages while collecting visitor contact information for future communication. The vulnerability represents a critical security oversight that exposes sensitive user data through improper access controls and data handling mechanisms.
The technical exploitation of this vulnerability occurs through the AJAX endpoint that processes subscription requests without adequate authentication verification or authorization checks. When authenticated attackers interact with the 'acx_csma_subscribe_ajax' function, they can bypass normal access restrictions and extract information about subscribed users including their names and email addresses. This represents a classic case of insufficient access control where the system fails to properly validate user permissions before exposing sensitive data. The vulnerability aligns with CWE-284 which addresses inadequate access control mechanisms and CWE-352 which covers cross-site request forgery issues that can lead to unauthorized data access. Attackers can leverage this flaw to gather personal information about website visitors, potentially enabling social engineering attacks, spam campaigns, or more sophisticated targeting operations.
The operational impact of this vulnerability extends beyond simple data exposure as it fundamentally undermines the trust relationship between website administrators and their visitors. Website owners who use this plugin for maintenance mode purposes expect that visitor subscription data will remain private and secure. However, the vulnerability allows unauthorized access to this information, creating potential legal and regulatory compliance issues under data protection frameworks such as gdpr and ccpa. The exposure of email addresses and names provides attackers with valuable contact information that can be used for phishing campaigns or other malicious activities. This vulnerability also affects the overall security posture of WordPress installations, as compromised plugins can serve as entry points for more extensive attacks on the entire website infrastructure. The attack vector requires minimal technical expertise and can be automated, making it particularly dangerous for widespread exploitation.
Mitigation strategies for CVE-2023-6922 should prioritize immediate plugin updates to versions that address the access control flaw. Website administrators must ensure they are running the latest version of the Acurax plugin where the 'acx_csma_subscribe_ajax' function properly validates user authentication and authorization before returning sensitive data. Additionally, implementing network-level security measures such as rate limiting on AJAX endpoints can help reduce the effectiveness of automated exploitation attempts. Security monitoring should include detection of unusual patterns in subscription data access, particularly from authenticated users who might not have legitimate reasons to request such information. Organizations should also consider implementing web application firewalls that can identify and block malicious requests targeting known vulnerable endpoints. The remediation process should include reviewing and cleaning up any compromised data that may have been accessed by attackers, while also conducting thorough security audits of other plugins and themes to identify similar access control vulnerabilities. Regular security assessments and vulnerability scanning should be implemented to proactively identify and address similar issues before they can be exploited by threat actors.