CVE-2011-4647 in Geeklog
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in the story creation feature in Geeklog 1.8.0 allow remote attackers to inject arbitrary web script or HTML via the (1) code or (2) raw BBcode tags.
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Analysis
by VulDB Data Team • 02/13/2019
The vulnerability identified as CVE-2011-4647 represents a critical cross-site scripting flaw within the Geeklog content management system version 1.8.0, specifically affecting the story creation functionality. This vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly filter malicious content submitted through the story creation interface. The flaw manifests when users attempt to create or edit stories, particularly when utilizing the code or raw BBcode tags that are designed to support rich text formatting and code insertion. Attackers can exploit this weakness by injecting malicious javascript code or html content that gets executed in the browsers of other users who view the affected stories.
The technical exploitation of this vulnerability occurs through the improper handling of user-supplied input within the story creation feature. When administrators or users submit content containing code or raw BBcode tags, the application fails to adequately sanitize these inputs before rendering them in the web interface. This lack of proper input filtering creates an environment where malicious scripts can be stored and subsequently executed in the context of other users' browsers. The vulnerability is classified as a classic reflected cross-site scripting issue, where the malicious payload is stored on the server and then served to other users without proper sanitization. According to CWE guidelines, this represents a CWE-79: Cross-site Scripting vulnerability, specifically manifesting as a stored XSS attack pattern where the malicious code persists in the application's database.
The operational impact of CVE-2011-4647 extends beyond simple script execution, potentially enabling attackers to perform session hijacking, steal user credentials, redirect users to malicious websites, or even gain administrative privileges within the affected Geeklog installation. The vulnerability affects all users who view stories containing the maliciously injected content, making it particularly dangerous in environments where multiple users interact with the system. Attackers could leverage this vulnerability to compromise user sessions, steal cookies, or inject additional malicious content that could propagate throughout the system. The attack vector is particularly concerning because it operates through legitimate content creation features, making it difficult to distinguish between benign user-generated content and malicious payloads. This vulnerability aligns with ATT&CK technique T1566.001 for Initial Access through spearphishing attachments, though in this case the attack occurs through content creation rather than email delivery.
Mitigation strategies for CVE-2011-4647 require immediate implementation of proper input sanitization and output encoding mechanisms throughout the Geeklog application. Organizations should implement comprehensive input validation that strips or encodes potentially dangerous characters and tags, particularly within the code and raw BBcode processing functionality. The most effective remediation involves upgrading to a patched version of Geeklog that addresses this specific vulnerability, as the original 1.8.0 release contains fundamental flaws in its content handling mechanisms. Additionally, administrators should implement proper content security policies and consider implementing a web application firewall to detect and prevent XSS attempts. Regular security audits of user input handling and output encoding mechanisms should be conducted to prevent similar vulnerabilities from emerging in other parts of the application. The vulnerability demonstrates the critical importance of proper input sanitization and the need for comprehensive security testing of all user-facing input handling components within web applications, particularly those that process rich text or code content.