CVE-2020-5780 in Email Subscribers
Summary
by MITRE
Missing Authentication for Critical Function in Icegram Email Subscribers & Newsletters Plugin for WordPress prior to version 4.5.6 allows a remote, unauthenticated attacker to conduct unauthenticated email forgery/spoofing.
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Analysis
by VulDB Data Team • 09/11/2020
The vulnerability identified as CVE-2020-5780 represents a critical authentication flaw within the Icegram Email Subscribers & Newsletters plugin for WordPress systems. This issue affects versions prior to 4.5.6 and exposes a significant security gap that allows remote attackers to exploit the system without requiring valid credentials. The flaw specifically targets the plugin's handling of critical functions related to email management and subscriber operations, creating an avenue for unauthorized manipulation of email communications.
The technical implementation of this vulnerability stems from inadequate validation of user authentication status when processing requests for critical email functions. Attackers can exploit this weakness to forge or spoof email messages by directly invoking the plugin's email sending mechanisms without proper authorization. The flaw operates at the application layer and leverages the plugin's API endpoints to bypass standard WordPress authentication checks. This allows malicious actors to send emails that appear to originate from legitimate sources within the WordPress installation, potentially leading to phishing attacks, spam distribution, or social engineering campaigns.
From an operational impact perspective, this vulnerability enables attackers to conduct unauthorized email spoofing campaigns that can severely damage the reputation of affected websites and their users. The unauthenticated nature of the attack means that even users without administrative privileges or legitimate access credentials can exploit this flaw. This vulnerability directly impacts the integrity and trustworthiness of email communications within WordPress environments, potentially leading to widespread distribution of malicious content or unauthorized marketing materials. The attack surface extends to any WordPress installation using the vulnerable plugin version, making it particularly concerning for organizations with multiple sites or those managing large subscriber lists.
The vulnerability aligns with CWE-306, which addresses missing authentication for critical functions, and represents a clear violation of the principle of least privilege in security design. From an adversary perspective, this flaw maps to ATT&CK technique T1566.001 for credential harvesting through phishing and T1190 for exploitation of vulnerabilities in web applications. Organizations should immediately implement patch management procedures to upgrade to version 4.5.6 or later of the Icegram plugin. Additional mitigations include implementing network-level restrictions on plugin endpoints, monitoring for unauthorized email sending activities, and conducting thorough security audits of WordPress installations. The vulnerability also highlights the importance of regular security assessments for third-party plugins and the need for organizations to maintain updated inventory of all installed WordPress components to prevent similar exposures in the future.