CVE-2016-9891 in DotClear
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in admin/media.php and admin/media_item.php in Dotclear before 2.11 allows remote authenticated users to inject arbitrary web script or HTML via the upfiletitle or media_title parameter (aka the media title).
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Analysis
by VulDB Data Team • 10/13/2022
The vulnerability described in CVE-2016-9891 represents a critical cross-site scripting flaw affecting the Dotclear content management system prior to version 2.11. This vulnerability exists in two administrative files: admin/media.php and admin/media_item.php, making it particularly concerning as it targets the administrative interface where privileged users manage media content. The flaw specifically affects authenticated users who possess administrative privileges, meaning that an attacker must first compromise an administrative account to exploit this vulnerability, though the impact remains severe given the elevated permissions involved.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the media management functionality of Dotclear. When administrators upload media files, they can assign titles to these files through the upfiletitle or media_title parameters. The application fails to properly sanitize or encode these parameters before rendering them in the web interface, creating an opportunity for malicious script injection. This allows attackers to execute arbitrary JavaScript code within the context of other users' browsers, potentially enabling session hijacking, credential theft, or further exploitation of the compromised administrative session.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a pathway to escalate privileges and compromise the entire administrative environment. Since the vulnerability affects administrative interfaces, successful exploitation could enable attackers to modify or delete media content, upload malicious files, or even modify other administrative settings. The fact that this affects authenticated users means that the attack vector is more contained but no less dangerous, as it leverages existing administrative access rather than requiring initial compromise through other means. This vulnerability aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the improper handling of user input in web applications.
From a threat modeling perspective, this vulnerability fits within the ATT&CK framework under the T1059.007 technique for Command and Scripting Interpreter, specifically JavaScript, as well as T1566.001 for Phishing with Malicious Attachments, since the attack requires an authenticated user to execute malicious payloads. The vulnerability also demonstrates characteristics of T1071.001 for Application Layer Protocol, as it exploits web application protocols to inject malicious content. Organizations using Dotclear versions prior to 2.11 face significant risk of persistent security breaches, particularly if they have administrative accounts with elevated privileges.
The mitigation strategy for this vulnerability requires immediate patching to version 2.11 or later, which includes proper input sanitization and output encoding for media title parameters. Administrators should also implement additional security measures such as regular security audits of administrative interfaces, monitoring for unusual file upload activities, and implementing proper access controls. The vulnerability highlights the importance of input validation in web applications and demonstrates how seemingly minor flaws in parameter handling can create significant security risks in administrative interfaces. Organizations should also consider implementing web application firewalls to provide additional protection layers and ensure that all administrative functions properly sanitize user input before processing or displaying it in web contexts.