The Email Subscribers & Newsletters Plugin for WordPress is prone to multiple security-bypass vulnerabilities. Attackers can exploit these issues to bypass certain security restrictions and perform unauthorized actions. This may aid in further attacks. Versions prior to Email Subscribers & Newsletters 4.2.3 are vulnerable.
Block external access at the network boundary, unless external parties require service.
If global access isn't needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.
Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of suspicious or anomalous activity. This may help detect malicious actions that an attacker may take after successfully exploiting vulnerabilities in applications. Review all applicable logs regularly.
Updates are available. Please see the references or vendor advisory for more information.