CVE-2006-7020 in phpwcms
Summary
by MITRE
CRLF injection vulnerability in (1) include/inc_act/act_formmailer.php and possibly (2) sample_ext_php/mail_file_form.php in phpwcms 1.2.5-DEV and earlier, and 1.1 before RC4, allows remote attackers to modify HTTP headers and send spam e-mail via a spoofed HTTP Referer (HTTP_REFERER).
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Analysis
by VulDB Data Team • 08/19/2018
The CVE-2006-7020 vulnerability represents a critical cross-site scripting and header injection flaw affecting phpwcms versions 1.2.5-DEV and earlier, as well as 1.1 before RC4. This vulnerability stems from inadequate input validation and sanitization within the web application's form mailer functionality, specifically in the act_formmailer.php and sample_ext_php/mail_file_form.php components. The flaw allows remote attackers to inject malicious carriage return and line feed characters into HTTP headers, enabling them to manipulate the application's behavior and potentially execute unauthorized actions.
The technical exploitation of this vulnerability occurs through the manipulation of the HTTP_REFERER header, which is commonly used by web applications to track user navigation. When phpwcms processes form submissions without properly sanitizing user input that gets incorporated into HTTP headers, attackers can inject CRLF sequences that break out of the intended header context. This injection allows attackers to modify subsequent HTTP headers, potentially redirecting traffic or injecting malicious content. The vulnerability specifically targets the Referer header, which is automatically populated by web browsers when navigating from one page to another, making it an accessible vector for exploitation.
The operational impact of this vulnerability extends beyond simple header manipulation to include potential spam email generation and unauthorized HTTP header modification. Attackers can leverage this flaw to send spam emails through the vulnerable application's mailer functionality, as the injected headers can be used to spoof the sender address or modify email routing. Additionally, the ability to manipulate HTTP headers opens doors for more sophisticated attacks including session hijacking, cache poisoning, and web cache deception. The vulnerability creates a persistent threat vector that can be exploited repeatedly, as the injection points remain in the application code without proper input validation mechanisms.
This vulnerability aligns with CWE-113, which specifically addresses improper neutralization of CRLF characters in HTTP headers, and corresponds to ATT&CK technique T1190 for exploitation of web applications. The attack surface is particularly concerning because it involves commonly used web application components that handle user input and generate HTTP responses. The flaw demonstrates poor input validation practices and highlights the critical importance of sanitizing all user-supplied data before incorporating it into HTTP headers or other system components. Organizations using affected phpwcms versions should immediately implement patches or apply input sanitization measures to prevent exploitation. The vulnerability underscores the necessity of implementing comprehensive security controls including proper header validation, input sanitization, and regular security assessments to prevent similar injection vulnerabilities in web applications.
The remediation approach should include immediate patching of the affected phpwcms versions, implementation of proper input validation and sanitization for all HTTP headers, and deployment of web application firewalls to detect and block malicious CRLF injection attempts. Security teams should also conduct thorough code reviews of similar components to identify and address potential injection vulnerabilities in other parts of the application. The vulnerability serves as a reminder of the critical importance of validating and sanitizing all user input, particularly in components that handle HTTP communication and header manipulation.