CVE-2007-1081 in TYPO3
Summary
by MITRE
The start function in class.t3lib_formmail.php in TYPO3 before 4.0.5, 4.1beta, and 4.1RC1 allows attackers to inject arbitrary email headers via unknown vectors. NOTE: some details were obtained from third party information.
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Analysis
by VulDB Data Team • 03/15/2021
The vulnerability identified as CVE-2007-1081 represents a critical email header injection flaw within the TYPO3 content management system. This vulnerability specifically affects the start function within the class.t3lib_formmail.php file, which is a core component responsible for handling form mail functionality in TYPO3 installations. The issue exists in versions prior to 4.0.5, 4.1beta, and 4.1RC1, making it a significant security concern for organizations running these outdated versions of the platform. The vulnerability allows malicious actors to inject arbitrary email headers, potentially enabling them to manipulate email delivery, redirect messages, or even facilitate spam activities.
The technical flaw stems from inadequate input validation and sanitization within the form mail processing function. When users submit forms that utilize TYPO3's mail functionality, the application fails to properly sanitize user-supplied data before incorporating it into email headers. This creates an injection vector where attackers can append malicious header fields such as 'To', 'Cc', 'Bcc', 'Subject', or custom headers that can alter the intended behavior of email transmission. The vulnerability's classification aligns with CWE-93, which specifically addresses improper neutralization of CRLF characters in email headers, and represents a variant of the broader header injection vulnerability pattern. The attack surface is particularly concerning as it leverages the legitimate mail functionality of the CMS, making it difficult to detect and distinguish from normal user activity.
The operational impact of this vulnerability extends beyond simple email manipulation and can lead to severe consequences for affected organizations. Attackers can exploit this flaw to send spam emails through the compromised TYPO3 installation, potentially damaging the organization's reputation and leading to blacklisting of their email servers. The vulnerability also enables more sophisticated attacks such as email redirection, where malicious emails are forwarded to unauthorized recipients, or the injection of phishing content in email headers. From an attacker's perspective, this vulnerability provides a means to conduct relay attacks, where the compromised TYPO3 server becomes an unwitting relay for spam or malicious email traffic. The implications are particularly serious in enterprise environments where email systems are tightly controlled and monitored, as the injection could bypass existing security measures that rely on email header validation.
Mitigation strategies for CVE-2007-1081 primarily focus on immediate version upgrades to patched releases of TYPO3. Organizations should prioritize upgrading to TYPO3 versions 4.0.5, 4.1beta, or 4.1RC1, which contain the necessary fixes for the header injection vulnerability. Additionally, implementing proper input validation at the application level can serve as a temporary workaround, although this approach is less reliable than official patches. Network-level protections such as email header filtering and monitoring for unusual header patterns can help detect exploitation attempts. Organizations should also consider implementing email authentication mechanisms like SPF, DKIM, and DMARC to mitigate the potential impact of any successful exploitation. The vulnerability's remediation aligns with the principle of least privilege and input sanitization practices recommended in the OWASP Top Ten and MITRE ATT&CK framework, particularly under the initial access and command and control categories. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar issues in other components of the web application stack, ensuring comprehensive protection against header injection attacks.