CVE-2013-5956 in Com Youtubegallery
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in includes/flvthumbnail.php in the Youtube Gallery (com_youtubegallery) component 3.4.0 for Joomla! allows remote attackers to inject arbitrary web script or HTML via the videofile parameter.
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Analysis
by VulDB Data Team • 05/12/2026
The CVE-2013-5956 vulnerability represents a critical cross-site scripting flaw within the Youtube Gallery component for Joomla! version 3.4.0, specifically affecting the includes/flvthumbnail.php file. This vulnerability classifies under CWE-79 as an improper neutralization of input during web output, where user-supplied data fails to be properly sanitized before being rendered in web pages. The flaw exists in the component's handling of the videofile parameter, which is processed without adequate input validation or output encoding mechanisms. Attackers can exploit this weakness by crafting malicious payloads in the videofile parameter that get executed in the context of other users' browsers when the vulnerable page is accessed, potentially leading to session hijacking, data theft, or malicious content injection.
The technical implementation of this vulnerability demonstrates a classic XSS attack vector where the application directly incorporates user-provided input from the videofile parameter into dynamically generated web content without proper sanitization. When a victim visits a page that includes the maliciously crafted videofile parameter, the embedded script executes in their browser within the security context of the vulnerable Joomla where administrators and regular users may have varying privilege levels, potentially allowing attackers to escalate their privileges through session manipulation.
The operational impact of CVE-2013-5956 extends beyond simple script injection, as it can enable attackers to compromise entire Joomla installations face significant risk of data breaches, unauthorized access to administrative interfaces, and potential compromise of entire web applications. The attack surface is particularly broad given that Joomla! was widely used across various industries, making this vulnerability a prime target for automated exploitation campaigns.
Mitigation strategies for CVE-2013-5956 should include immediate patching of the affected Youtube Gallery component to version 3.4.1 or later, which contains the necessary input validation and output encoding fixes. Organizations should implement comprehensive input sanitization measures that filter or escape all user-supplied parameters before processing, particularly for parameters that are directly rendered in web output. Web application firewalls can provide additional protection layers by detecting and blocking malicious payloads in the videofile parameter. Security teams should conduct thorough vulnerability assessments to identify all instances of the affected component across their Joomla! installations, as the vulnerability may exist in multiple versions or custom implementations. Regular security monitoring and log analysis should be implemented to detect potential exploitation attempts, while security awareness training for administrators can help prevent social engineering attacks that might leverage this vulnerability. The remediation process should also include implementing proper access controls and privilege separation to limit the damage that could occur even if exploitation succeeds, aligning with defense-in-depth principles recommended in industry standards such as NIST SP 800-53.