CVE-2010-4939 in MailForm
Summary
by MITRE
PHP remote file inclusion vulnerability in index.php in MailForm 1.2 allows remote attackers to execute arbitrary PHP code via a URL in the theme parameter.
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Analysis
by VulDB Data Team • 09/21/2025
The CVE-2010-4939 vulnerability represents a critical remote file inclusion flaw in the MailForm 1.2 web application that exposes systems to arbitrary code execution attacks. This vulnerability specifically affects the index.php file within the application's codebase and stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data. The flaw manifests when the application processes the theme parameter without adequate filtering, allowing malicious actors to inject URLs that point to remote malicious files. This type of vulnerability falls under the category of CWE-98 Improper Input Validation and specifically aligns with CWE-88 Command Injection, as the application directly incorporates user-controllable input into file inclusion operations without proper sanitization.
The technical exploitation of this vulnerability enables attackers to leverage the remote file inclusion mechanism by crafting malicious URLs within the theme parameter that reference external malicious PHP scripts. When the vulnerable MailForm application processes this input, it attempts to include and execute the remote file, effectively granting the attacker complete control over the application's execution environment. The attack vector operates through standard HTTP requests where the malicious payload is transmitted as part of the URL parameters, making it particularly insidious as it can be delivered through simple web browser interactions or automated attack tools. This vulnerability directly maps to ATT&CK technique T1505.003 Server-side Include Injection, where adversaries leverage server-side code execution capabilities to inject malicious content.
The operational impact of CVE-2010-4939 extends far beyond simple code execution, as it provides attackers with complete system compromise capabilities. Once exploited, attackers can establish persistent backdoors, escalate privileges, exfiltrate sensitive data, and use the compromised server as a launchpad for further attacks within the network infrastructure. The vulnerability affects any system running the vulnerable MailForm 1.2 version and demonstrates a fundamental lack of secure coding practices in input handling and file inclusion operations. Organizations may face severe consequences including data breaches, regulatory penalties, and reputational damage when such vulnerabilities remain unpatched, as the attack surface provides complete control over the affected web application and underlying server environment.
Mitigation strategies for CVE-2010-4939 must address both immediate remediation and long-term security hardening measures. The primary solution involves applying the official security patch released by the MailForm developers to update the vulnerable application to a secure version. Additionally, implementing input validation and sanitization mechanisms can provide defense-in-depth protection, ensuring that all user-supplied parameters undergo strict validation before processing. Network-level protections such as web application firewalls and intrusion prevention systems can help detect and block malicious requests targeting this vulnerability. Security configurations should enforce strict file inclusion policies that prevent dynamic inclusion of external resources, while implementing proper access controls and monitoring systems to detect anomalous file inclusion activities. Organizations should also conduct comprehensive security assessments to identify similar vulnerabilities in other applications and establish secure coding practices that align with industry standards including OWASP Top Ten and NIST Cybersecurity Framework guidelines to prevent future occurrences of such critical flaws.