CVE-2015-8759 in TYPO3
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the typoLink function in TYPO3 6.2.x before 6.2.16 and 7.x before 7.6.1 allows remote authenticated editors to inject arbitrary web script or HTML via a link field.
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Analysis
by VulDB Data Team • 06/06/2018
The CVE-2015-8759 vulnerability represents a critical cross-site scripting flaw within the TYPO3 content management system that specifically targets the typoLink function implementation. This vulnerability affects TYPO3 versions 6.2.x prior to 6.2.16 and 7.x prior to 7.6.1, creating a significant security risk for organizations relying on these older versions. The flaw allows authenticated editors with sufficient privileges to inject malicious web scripts or HTML code through link fields, potentially compromising the integrity of the entire CMS environment. The vulnerability stems from insufficient input validation and output encoding mechanisms within the typoLink function, which processes and renders links within the TYPO3 interface.
The technical exploitation of this vulnerability occurs when authenticated users with editor permissions manipulate link fields in the TYPO3 backend. These users can craft malicious payloads that get executed when other users view pages containing the compromised links. The vulnerability operates at the application layer and falls under CWE-79, which specifically addresses cross-site scripting flaws in software applications. The attack vector is particularly concerning because it leverages legitimate user privileges, making it difficult to detect through traditional network monitoring. The typoLink function's failure to properly sanitize user-supplied input creates an environment where malicious scripts can be stored and subsequently executed in the browsers of other users who access the affected content.
The operational impact of CVE-2015-8759 extends beyond simple script injection, as it can lead to complete session hijacking, data theft, and potential lateral movement within the compromised environment. An attacker with access to an editor account can use this vulnerability to steal cookies, redirect users to malicious sites, or even execute commands on behalf of other users. The vulnerability affects the core functionality of TYPO3's link handling system, potentially compromising the integrity of all content managed through the platform. Organizations may experience unauthorized access to sensitive information, modification of website content, and potential compromise of user authentication mechanisms. The attack can be particularly damaging in enterprise environments where TYPO3 serves as a critical component of digital infrastructure.
Mitigation strategies for CVE-2015-8759 should prioritize immediate patching of affected TYPO3 versions to the recommended secure releases. Organizations must ensure that all editor accounts maintain strong authentication mechanisms including multi-factor authentication and regular credential rotation. Input validation and output encoding should be strengthened throughout the TYPO3 application to prevent similar vulnerabilities from emerging. Security monitoring should include detection of anomalous link field modifications and regular security audits of content management systems. The vulnerability aligns with ATT&CK technique T1566 which covers social engineering attacks through malicious links, making it particularly relevant for organizations implementing security awareness training programs. Network segmentation and least privilege access controls should be enforced to limit the potential damage from compromised editor accounts, while regular security assessments should verify that all CMS components remain up to date with security patches.