CVE-2017-6955 in Invite Anyone Plugin
Summary
by MITRE
An issue was discovered in by-email/by-email.php in the Invite Anyone plugin before 1.3.15 for WordPress. A user is able to change the subject and the body of the invitation mail that should be immutable, which facilitates a social engineering attack.
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Analysis
by VulDB Data Team • 08/25/2024
The vulnerability identified as CVE-2017-6955 affects the Invite Anyone plugin for WordPress, specifically targeting the by-email/by-email.php component in versions prior to 1.3.15. This security flaw represents a critical weakness in the plugin's access control mechanisms and data integrity protections. The vulnerability allows authenticated users to manipulate the subject line and body content of invitation emails that are intended to remain immutable, fundamentally undermining the security posture of the plugin's email functionality.
This technical flaw constitutes a direct violation of data integrity principles and represents a privilege escalation vulnerability where legitimate users can modify system-generated content. The vulnerability exists due to insufficient input validation and sanitization within the email composition process, allowing attackers to inject malicious content or manipulate the communication flow. From a cybersecurity perspective, this issue directly maps to CWE-20, which describes improper input validation, and CWE-79, which addresses cross-site scripting vulnerabilities that can result from inadequate data sanitization. The flaw enables attackers to craft deceptive email content that appears to originate from legitimate system communications, creating opportunities for phishing attacks and social engineering campaigns.
The operational impact of CVE-2017-6955 extends beyond simple content manipulation, as it provides attackers with a sophisticated vector for conducting targeted social engineering attacks. When users receive invitation emails with altered subject lines and body content, they may be misled into believing these communications are authentic system notifications, potentially leading to credential theft, malware distribution, or other malicious activities. The vulnerability particularly affects WordPress environments where the Invite Anyone plugin is used for user invitation management, creating a persistent threat vector that can be exploited repeatedly. Attackers can leverage this weakness to craft convincing phishing emails that bypass traditional email filtering mechanisms, as the emails appear to come from legitimate system sources.
The attack surface for this vulnerability encompasses any WordPress installation using the affected plugin version, making it particularly concerning for organizations with large user bases or those managing sensitive community platforms. Security professionals should consider this issue in relation to ATT&CK technique T1566, which covers phishing campaigns, and T1078, which addresses valid accounts usage. The vulnerability also aligns with the broader category of credential harvesting attacks where attackers manipulate communication channels to gain trust and extract sensitive information. Organizations should implement immediate mitigation strategies including plugin updates to version 1.3.15 or later, along with enhanced monitoring of email communication patterns and user behavior analytics to detect potential exploitation attempts. Additionally, administrators should review and strengthen their overall WordPress security posture through regular vulnerability assessments and security audits to prevent similar issues from arising in other components of their web infrastructure.