CVE-2009-4953 in Sg Userdata
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Userdata Create/Edit (sg_userdata) extension before 0.91.0 for TYPO3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 01/07/2018
The CVE-2009-4953 vulnerability represents a critical cross-site scripting flaw within the TYPO3 content management system's Userdata Create/Edit extension. This vulnerability affects versions prior to 0.91.0 and exposes TYPO3 installations to remote code execution risks through malicious web script injection. The flaw resides in the extension's handling of user input during data creation and editing operations, creating an avenue for attackers to manipulate the application's behavior through crafted payloads. The vulnerability's classification as a persistent XSS issue means that malicious scripts can be stored on the server and executed whenever legitimate users access the affected pages, potentially leading to session hijacking, data theft, or further exploitation of the compromised system.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the sg_userdata extension's codebase. Attackers can exploit unspecified vectors to inject malicious HTML or JavaScript code that gets executed in the context of other users' browsers. This weakness directly relates to CWE-79, which defines Cross-Site Scripting as a common web application vulnerability where untrusted data is embedded into web pages without proper validation or escaping. The vulnerability's impact extends beyond simple script execution as it can be leveraged to perform actions on behalf of authenticated users, potentially compromising the entire TYPO3 installation's security posture.
The operational impact of CVE-2009-4953 is significant for organizations running affected TYPO3 versions, as it enables attackers to gain unauthorized access to user sessions and potentially escalate privileges within the CMS environment. Remote attackers can craft malicious payloads that persist in the database, ensuring that every subsequent access to the vulnerable pages triggers the execution of the injected code. This persistent nature of the vulnerability makes it particularly dangerous for content management systems where user-generated content is common, as the attack surface expands to include all user interaction points within the affected extension. The vulnerability also aligns with ATT&CK technique T1566, which covers the exploitation of web application vulnerabilities for initial access and privilege escalation.
Organizations should immediately upgrade to TYPO3 version 0.91.0 or later to remediate this vulnerability, as no effective workarounds exist for the underlying code flaw. Security administrators must conduct comprehensive vulnerability assessments across all TYPO3 installations to identify potentially affected extensions and ensure proper patch management processes are in place. Additional mitigations include implementing robust input validation mechanisms, applying proper output encoding for all user-generated content, and establishing network-level protections such as web application firewalls to detect and block malicious payloads. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and the necessity of regular security audits to prevent exploitation of known vulnerabilities in content management systems.