CVE-2006-2944 in FORM2MAIL
Summary
by MITRE
Unspecified vulnerability in CGI-RESCUE FORM2MAIL 1.21 and earlier allows remote attackers to inject email headers, which facilitates sending spam messages. NOTE: the details for this issue are obtained from third party information.
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Analysis
by VulDB Data Team • 07/28/2018
The vulnerability identified as CVE-2006-2944 affects CGI-RESCUE FORM2MAIL version 1.21 and earlier, representing a critical security flaw in web-based email form processing systems. This issue stems from inadequate input validation mechanisms within the form-to-mail script that processes user-submitted data through web forms. The vulnerability enables remote attackers to manipulate email header fields during message transmission, effectively bypassing normal email security controls and allowing unauthorized message routing. The flaw operates at the application layer where user input is directly incorporated into email headers without proper sanitization or validation, creating a pathway for malicious actors to exploit the system for spam distribution. This type of vulnerability aligns with CWE-74, which describes improper neutralization of special elements in output used by a downstream component, specifically in the context of email header injection. The security implications extend beyond simple spam delivery as this vulnerability can be leveraged for more sophisticated attacks including phishing campaigns, email spoofing, and potentially as a stepping stone for further system compromise.
The technical exploitation of this vulnerability occurs when attackers submit specially crafted form data that includes malicious email header fields such as From, To, Subject, or Reply-To fields. These manipulated headers can contain additional email addresses, forged sender information, or even additional header lines that alter the message routing behavior. The vulnerability exists because the form-to-mail script does not properly validate or sanitize user input before incorporating it into the email headers, allowing attackers to inject arbitrary header content. This injection capability enables attackers to send emails that appear to originate from legitimate sources while actually being routed through compromised systems. The impact extends to email servers that may not properly validate incoming headers, potentially allowing the forged messages to bypass spam filters and deliver malicious content to recipients. Attackers can leverage this vulnerability to flood email systems with spam messages, potentially using the compromised system as a spam relay, or to send phishing emails that appear to come from trusted sources within the organization's network.
The operational impact of this vulnerability creates significant risks for organizations relying on CGI-based form processing systems for customer communication, support ticket submission, or other web-based email services. Once exploited, the vulnerability can enable attackers to generate large volumes of spam messages that may be delivered through the compromised system's email infrastructure, potentially leading to blacklisting of the organization's IP addresses or domain names. The vulnerability also poses risks to email server reputation and can result in legitimate emails being filtered or rejected due to the spam activity generated by the compromised system. Organizations may face legal and regulatory consequences if their systems are used to distribute spam or phishing content, as the compromised system becomes a vector for malicious email traffic that can be traced back to the organization's infrastructure. The vulnerability's remote nature means that attackers can exploit it without requiring local system access, making it particularly dangerous as it can be targeted from anywhere on the internet.
Mitigation strategies for this vulnerability require immediate implementation of input validation and sanitization measures within the form-to-mail processing scripts. Organizations should upgrade to versions of CGI-RESCUE FORM2MAIL that contain proper input validation mechanisms and header sanitization functions. The recommended approach includes implementing strict validation of all user input fields to ensure they conform to expected email address formats and do not contain malicious header injection sequences. Security measures should include filtering out or escaping special characters that could be used to manipulate email headers, particularly carriage return and line feed characters that are fundamental to email header injection attacks. Network-level protections such as email filtering systems and spam detection mechanisms should be enhanced to monitor for unusual email traffic patterns that may indicate exploitation of this vulnerability. Additionally, organizations should implement proper access controls and monitoring of form submission activities to detect unauthorized usage patterns that could indicate exploitation attempts. The remediation process should also include regular security assessments of web applications and form processing systems to identify similar vulnerabilities in other components of the email infrastructure. This vulnerability highlights the importance of secure coding practices and proper input validation as outlined in the OWASP Top Ten security risks, specifically addressing the need for proper sanitization of user inputs in web applications that handle email processing functions.