CVE-2016-7902 in DotClear
Summary
by MITRE
Unrestricted file upload vulnerability in the fileUnzip->unzip method in Dotclear before 2.10.3 allows remote authenticated users with permissions to manage media items to execute arbitrary code by uploading a ZIP file containing a file with a crafted extension, as demonstrated by .php.txt or .php%20.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability CVE-2016-7902 represents a critical unrestricted file upload flaw in the Dotclear content management system prior to version 2.10.3. This vulnerability resides within the fileUnzip->unzip method and specifically targets the media management functionality that allows authenticated users to upload files. The flaw enables attackers with appropriate permissions to bypass normal file validation mechanisms and execute arbitrary code on the target system through carefully crafted file uploads.
The technical exploitation of this vulnerability relies on the improper handling of file extensions during the decompression process. When users upload ZIP archives containing files with extensions such as .php.txt or .php%20, the application fails to properly validate or sanitize these filenames during extraction. This oversight creates a path for attackers to upload malicious PHP files that appear harmless due to their extensions but are actually executable scripts when extracted. The vulnerability demonstrates a classic path traversal and file extension manipulation attack vector that bypasses typical security controls.
From an operational perspective, this vulnerability poses significant risks to Dotclear installations as it allows authenticated attackers with media management privileges to achieve remote code execution. The impact extends beyond simple file manipulation since successful exploitation can lead to complete system compromise, data exfiltration, and potential lateral movement within network environments. The vulnerability affects any system running Dotclear versions before 2.10.3 where users have the ability to upload media files, making it particularly dangerous in multi-user environments or when administrative privileges are granted to untrusted users.
The vulnerability aligns with CWE-434, which specifically addresses "Unrestricted Upload of File with Dangerous Type," and demonstrates characteristics consistent with ATT&CK technique T1190, "Exploit Public-Facing Application." Organizations using Dotclear should immediately implement the recommended patch updates to version 2.10.3 or later, which addresses the file validation and sanitization issues in the fileUnzip->unzip method. Additional mitigations include implementing strict file type validation, enforcing proper file extension checks, and restricting upload permissions to only trusted users. Network segmentation and monitoring for suspicious file upload activities can also help detect potential exploitation attempts. The vulnerability underscores the importance of proper input validation and secure file handling practices in web applications, particularly those dealing with user-uploaded content that undergoes decompression or processing operations.