CVE-2024-5703 is a vulnerability classified under CWE-862 (Missing Authorization) affecting the WordPress plugin 'Email Subscribers by Icegram Express – Email Marketing, Newsletters, Automation for WordPress & WooCommerce.' This plugin is widely used for managing email marketing campaigns and subscriber lists. The vulnerability arises because the plugin's API lacks proper capability checks, allowing any authenticated user with Subscriber-level permissions or higher to access the API endpoints. Through this unauthorized API access, attackers can add, modify, or delete audience users, thereby compromising the integrity of subscriber data. The flaw affects all versions up to and including 5.7.26. Exploitation requires no user interaction but does require authentication at a low privilege level, which is often easy to obtain in WordPress environments due to common user roles. The vulnerability does not expose confidential data directly nor does it impact system availability. The CVSS v3.1 base score is 4.3, indicating a medium severity level, with the vector highlighting network attack vector, low attack complexity, and privileges required. No patches or exploits are currently publicly available, but the risk remains significant for sites relying on this plugin for subscriber management. The vulnerability could be leveraged to manipulate mailing lists, potentially enabling phishing or spam campaigns originating from compromised subscriber data.

The primary impact of CVE-2024-5703 is on the integrity of subscriber data managed by the affected plugin. Unauthorized modification or deletion of audience users can disrupt marketing campaigns, cause loss of subscriber trust, and potentially facilitate further attacks such as phishing or spam by injecting malicious recipients or removing legitimate ones. While confidentiality and availability are not directly compromised, the manipulation of subscriber lists can have reputational and operational consequences for organizations. Attackers with Subscriber-level access, which is a low privilege role, can exploit this vulnerability, increasing the risk in environments with multiple users or weak access controls. Organizations relying heavily on WordPress and WooCommerce for e-commerce and marketing may face disruptions in customer engagement and potential regulatory compliance issues if subscriber data is mishandled. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as the vulnerability is publicly disclosed.

To mitigate CVE-2024-5703, organizations should immediately update the 'Email Subscribers by Icegram Express' plugin to a version that includes proper authorization checks once available. Until a patch is released, administrators should disable the plugin's API if it is not essential to operations, thereby preventing unauthorized API access. Additionally, review and tighten user role assignments to ensure that Subscriber-level accounts are limited and monitored, minimizing the number of users with potential to exploit this flaw. Implement strong authentication mechanisms such as multi-factor authentication (MFA) for all WordPress users to reduce the risk of account compromise. Regularly audit user activity logs for suspicious API usage or subscriber list changes. Employ web application firewalls (WAFs) with custom rules to detect and block unauthorized API calls targeting the plugin endpoints. Finally, maintain regular backups of subscriber data to enable recovery in case of unauthorized modifications or deletions.