CVE-2013-5576 in Joomla
Summary
by MITRE
administrator/components/com_media/helpers/media.php in the media manager in Joomla! 2.5.x before 2.5.14 and 3.x before 3.1.5 allows remote authenticated users or remote attackers to bypass intended access restrictions and upload files with dangerous extensions via a filename with a trailing . (dot), as exploited in the wild in August 2013.
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Analysis
by VulDB Data Team • 12/24/2024
The vulnerability identified as CVE-2013-5576 represents a critical access control flaw within the Joomla! content management system that affected versions prior to 2.5.14 and 3.1.5. This issue resides in the media manager component located at administrator/components/com_media/helpers/media.php, where improper validation of file extensions allows malicious actors to circumvent security restrictions. The flaw specifically exploits the way the system processes filenames containing trailing dots, enabling attackers to upload potentially harmful files with extensions that would normally be blocked by the system's security mechanisms.
The technical implementation of this vulnerability stems from inadequate input validation within the file upload processing logic. When a file is uploaded with a filename containing a trailing dot followed by a potentially dangerous extension, the system fails to properly sanitize or validate the filename before processing. This occurs because the validation routine does not adequately strip or normalize trailing characters from filenames, allowing attackers to append malicious extensions that bypass the intended security checks. The vulnerability is particularly dangerous because it operates at the file system level where uploaded files are processed and stored, potentially allowing remote code execution or other malicious activities.
The operational impact of this vulnerability is severe as it provides attackers with a method to bypass authentication requirements and upload malicious files to the web server. Attackers can leverage this flaw to upload web shells, malicious scripts, or other harmful payloads that can compromise the entire Joomla installation. The vulnerability was actively exploited in the wild during August 2013, demonstrating its real-world threat level and the urgency of addressing such security gaps. Organizations running affected versions of Joomla! were at significant risk of complete system compromise, as the vulnerability allowed unauthorized file uploads that could lead to data breaches, service disruption, and further lateral movement within network infrastructures.
This vulnerability aligns with CWE-22, which addresses improper limitation of a pathname to a restricted directory, and CWE-434, which covers uncontrolled file upload. The attack pattern follows ATT&CK technique T1190, known as "Exploit Public-Facing Application," where adversaries target web applications to gain unauthorized access. The flaw demonstrates the critical importance of proper input validation and sanitization in web applications, particularly in file handling components. Organizations should implement immediate patches to address this vulnerability, while also reviewing their overall file upload security practices to prevent similar issues. The remediation process requires updating to the patched versions of Joomla! and implementing additional security measures such as strict file type validation, proper file extension checking, and robust access controls to prevent unauthorized file uploads.