CVE-2009-4706 in Mailform
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Mailform (mailform) extension before 0.9.24 for TYPO3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 05/02/2026
The CVE-2009-4706 vulnerability represents a critical cross-site scripting flaw within the Mailform extension for TYPO3 content management system. This vulnerability specifically affects versions prior to 0.9.24 and exposes web applications to remote code execution through malicious script injection attacks. The vulnerability stems from insufficient input validation and output sanitization mechanisms within the mailform extension's processing logic, creating an exploitable entry point for attackers to manipulate web application behavior through crafted user inputs.
The technical nature of this vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as weaknesses in web applications that allow attackers to inject malicious scripts into web pages viewed by other users. The flaw operates by failing to properly sanitize user-supplied data before rendering it within web page contexts, enabling attackers to inject HTML content or JavaScript code that executes in the victim's browser session. This occurs through unspecified vectors within the mailform extension's form handling mechanisms, where user inputs are directly incorporated into generated HTML without appropriate security filtering or encoding.
From an operational impact perspective, this vulnerability poses significant risks to organizations utilizing TYPO3 with the mailform extension, as it enables attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and defacement of web applications. The remote nature of the attack means that exploitation can occur without requiring local system access or authentication, making it particularly dangerous for web applications that process user-submitted data. Attackers can craft malicious payloads that persist in the application's user interface, potentially affecting multiple users who interact with the compromised form functionality.
The vulnerability demonstrates the critical importance of input validation and output encoding practices in web application security, particularly within content management systems that handle user-generated content. Organizations should implement comprehensive security measures including regular patch management, input sanitization, and output encoding to prevent such vulnerabilities from being exploited. The ATT&CK framework categorizes this type of vulnerability under the T1190 technique for exploit public-facing application, highlighting the need for robust application security controls and regular security assessments to identify and remediate such weaknesses before they can be exploited by malicious actors. Proper mitigation requires updating to the patched version 0.9.24 or later, implementing additional security layers such as content security policies, and conducting thorough security reviews of all web application components that process user inputs.