CVE-2008-4903 in Typo
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the leave comment (feedback) feature in Typo 5.1.3 and earlier allows remote attackers to inject arbitrary web script or HTML via the (1) comment[author] (Name) and (2) comment[url] (Website) parameters.
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Analysis
by VulDB Data Team • 10/13/2018
The CVE-2008-4903 vulnerability represents a critical cross-site scripting flaw discovered in Typo 5.1.3 and earlier versions, specifically targeting the leave comment feedback functionality. This vulnerability resides within the web application's input validation mechanisms, where user-supplied data from comment author and comment url parameters is not properly sanitized before being rendered back to other users. The flaw enables malicious actors to inject arbitrary web scripts or HTML content through these specific input fields, creating a persistent security risk that affects all users interacting with the vulnerable system.
The technical implementation of this vulnerability stems from insufficient output encoding and input validation within the comment processing pipeline. When users submit comments through the feedback system, the application fails to properly escape or filter special characters in the author name and website URL fields. This allows attackers to craft malicious payloads that can execute within the context of other users' browsers, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability specifically affects the comment[author] and comment[url] parameters, which are commonly used in web applications to collect user feedback and establish user profiles.
The operational impact of this vulnerability extends beyond simple script injection, as it creates a persistent threat vector that can be exploited across multiple user sessions. Attackers can leverage this flaw to execute malicious code in the browser context of other users, potentially gaining access to their sessions or sensitive information. The vulnerability affects the entire user base of affected Typo installations, making it particularly dangerous in environments where multiple users interact with the feedback system. This type of vulnerability directly violates security principles outlined in the OWASP Top Ten, specifically addressing the XSS category of web application vulnerabilities that can lead to unauthorized access and data compromise.
The exploitation of this vulnerability aligns with several ATT&CK framework techniques including T1059.007 for command and script injection, and T1566 for social engineering through malicious links. Organizations running affected Typo versions face significant risk of credential theft, session hijacking, and potential data exfiltration. The vulnerability demonstrates the critical importance of input validation and output encoding practices that are fundamental to preventing XSS attacks. Security practitioners should consider implementing proper HTML entity encoding for all user-supplied input fields, particularly those that are rendered back to other users within the application interface.
Mitigation strategies for CVE-2008-4903 include immediate upgrade to Typo versions 5.1.4 or later where this vulnerability has been addressed through proper input sanitization and output encoding. Organizations should also implement comprehensive input validation mechanisms that sanitize all user-supplied data before processing, and apply proper HTML escaping techniques to prevent script execution in rendered content. The fix typically involves implementing Content Security Policy headers and ensuring that all user-generated content is properly encoded when displayed to other users. Additionally, regular security assessments and input validation testing should be conducted to identify and remediate similar vulnerabilities in web applications.
This vulnerability exemplifies the common pattern of XSS flaws in web applications where insufficient sanitization of user inputs leads to persistent security risks. The flaw demonstrates how seemingly innocuous feedback systems can become attack vectors when proper security measures are not implemented. Organizations should prioritize updating vulnerable applications and implementing robust security controls including regular vulnerability scanning, proper input validation, and comprehensive security testing to prevent similar issues from occurring in their web applications. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date software and implementing proper security controls throughout the application development lifecycle.