CVE-2017-8101 in Serendipity
Summary
by MITRE
There is CSRF in Serendipity 2.0.5, allowing attackers to install any themes via a GET request.
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Analysis
by VulDB Data Team • 12/02/2022
The vulnerability identified as CVE-2017-8101 represents a critical cross-site request forgery flaw in Serendipity 2.0.5 content management system. This weakness allows malicious actors to manipulate the application's functionality through crafted web requests, specifically targeting the theme installation mechanism. The vulnerability exists due to insufficient validation of request origins and lack of proper anti-CSRF token implementation within the theme installation endpoint. Attackers can exploit this by crafting malicious links or pages that, when visited by an authenticated administrator, automatically trigger theme installation without explicit user consent. The flaw enables unauthorized modification of the website's appearance and potentially introduces malicious code execution capabilities through compromised themes. This vulnerability directly maps to CWE-352, which categorizes cross-site request forgery as a serious security weakness affecting web applications. The attack vector operates through the GET request method, which should typically be idempotent and safe for data retrieval but has been improperly implemented to perform destructive operations. The impact extends beyond simple theme changes as malicious themes could include backdoors, malicious scripts, or other payload delivery mechanisms that compromise the entire web application infrastructure.
The operational impact of this CSRF vulnerability is severe and multifaceted. An attacker who successfully exploits this flaw can install arbitrary themes, which may contain malicious code that executes in the context of the victim's browser session. This capability allows for persistent compromise of the web application, enabling data exfiltration, session hijacking, or further attack escalation. The vulnerability is particularly dangerous because it requires no special privileges beyond the ability to access the vulnerable web application, and it can be exploited through social engineering techniques such as phishing emails or compromised websites. The GET-based approach makes detection more challenging as these requests are often logged in web server access logs and may appear legitimate to security monitoring systems. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and script injection through web application interfaces, and T1071.001 for application layer protocol usage in web services. The exploitation process typically involves crafting a malicious webpage that automatically submits a GET request to the theme installation endpoint, leveraging the authenticated session cookies of the target user.
Mitigation strategies for CVE-2017-8101 require immediate implementation of proper CSRF protection mechanisms within the Serendipity application. Organizations should implement anti-CSRF tokens that are validated for each request modification operation, ensuring that requests originate from legitimate sources within the application. The fix involves adding unique, unpredictable tokens to all state-changing requests and validating these tokens server-side before processing any theme installation operations. Additionally, the application should enforce proper request origin validation and implement strict access controls that verify user authentication and authorization for each administrative function. Security headers such as Content Security Policy should be configured to prevent unauthorized script execution and restrict the sources from which content can be loaded. Regular security updates and patches should be applied immediately upon availability, as this vulnerability was addressed in subsequent versions of Serendipity. Network monitoring should include detection of unusual GET requests to administrative endpoints, and web application firewalls should be configured to block suspicious patterns. The remediation process should also involve comprehensive security testing including penetration testing and code review to ensure that similar vulnerabilities do not exist in other parts of the application. Organizations should implement principle of least privilege for administrative accounts and consider multi-factor authentication to reduce the impact of any potential compromise. Regular security awareness training for administrators helps prevent social engineering attacks that may exploit this vulnerability, and implementing proper session management with secure cookie attributes further protects against session hijacking attempts that could leverage this CSRF weakness.