CVE-2018-6905 in Typo
Summary
by MITRE
The page module in TYPO3 before 8.7.11, and 9.1.0, has XSS via $GLOBALS['TYPO3_CONF_VARS']['SYS']['sitename'], as demonstrated by an admin entering a crafted site name during the installation process.
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Analysis
by VulDB Data Team • 02/27/2023
The vulnerability CVE-2018-6905 represents a cross-site scripting flaw in the TYPO3 content management system that specifically targets the page module functionality. This issue affects versions prior to 8.7.11 and 9.1.0, making it a significant concern for organizations running these older versions of the platform. The vulnerability arises from insufficient input validation and output escaping mechanisms when handling the sitename configuration parameter stored in $GLOBALS['TYPO3_CONF_VARS']['SYS']['sitename']. During the installation process, administrators can enter a crafted site name that, when subsequently rendered in the page module, executes malicious scripts in the context of other users' browsers.
The technical exploitation of this vulnerability occurs through the improper handling of user-supplied input within the TYPO3 administration interface. When an administrator inputs a malicious site name containing script tags or other malicious code during installation, this input is stored in the system configuration without adequate sanitization. Subsequently, when the page module displays this sitename value, typically in administrative interfaces or configuration screens, the stored malicious code executes in the browser context of any user who views these pages. This creates a classic reflected cross-site scripting scenario where the malicious payload is delivered through the application's own interface rather than being injected from external sources.
From an operational perspective, this vulnerability poses substantial risks to TYPO3 installations as it allows attackers to execute arbitrary JavaScript code in the context of authenticated administrator sessions. The impact extends beyond simple data theft, as attackers can potentially escalate privileges, modify content, access sensitive administrative functions, or even compromise the entire web application. The vulnerability is particularly dangerous because it can be exploited during the initial installation phase, meaning that an attacker who gains access to the installation environment can immediately establish a persistent backdoor. This aligns with CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output escaping, and follows ATT&CK technique T1059.007 for script injection attacks.
Organizations should prioritize immediate patching of affected TYPO3 versions to address this vulnerability, as the risk of exploitation increases with the longevity of the installation. The recommended mitigation strategy involves upgrading to TYPO3 versions 8.7.11 or 9.1.0, which contain the necessary security fixes. Additionally, administrators should implement proper input validation measures, including sanitizing all user-supplied configuration values and employing Content Security Policy headers to limit the execution of unauthorized scripts. Regular security auditing of configuration parameters and monitoring of installation processes can help detect potential exploitation attempts, while restricting administrative access to trusted users only reduces the attack surface. The vulnerability demonstrates the critical importance of validating and sanitizing all user inputs in web applications, particularly within administrative interfaces where elevated privileges can lead to complete system compromise.