CVE-2021-47749
Local File Inclusion in YouPHPTube <= 7.8 via 'lang' Parameter
Publication date: 2026-01-13
Last updated on: 2026-01-13
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| youphptube | youphptube | to 7.8 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-22 | The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a Local File Inclusion (LFI) and directory traversal flaw in YouPHPTube versions up to 7.8. It occurs because the application improperly handles the 'lang' parameter in GET requests, specifically in the locale/function.php file. Attackers can manipulate this parameter with directory traversal sequences (like '../') to include and view arbitrary PHP files outside the intended directory without authentication. This allows them to read sensitive files on the server by tricking the application into including files it should not. [2, 3]
How can this vulnerability impact me? :
This vulnerability can have a significant impact by allowing unauthenticated attackers to read arbitrary files on the server, potentially exposing sensitive information such as configuration files or source code. This exposure can lead to further exploitation or compromise of the system. Since the vulnerability does not require any privileges or user interaction and is remotely exploitable, it poses a high risk to confidentiality. [2, 3]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by attempting to exploit the local file inclusion via the 'lang' parameter in GET requests to the YouPHPTube application. For example, you can send HTTP requests to the vulnerable server with directory traversal payloads in the 'lang' parameter to see if arbitrary files are included. A sample command using curl would be: curl -v "http://<target>/youphptube/?lang=../../phpinfo". If the response includes PHP configuration details or other unexpected file contents, the system is vulnerable. Monitoring web server logs for suspicious requests containing directory traversal sequences in the 'lang' parameter can also help detect exploitation attempts. [3]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting access to the affected YouPHPTube installation, especially the locale/function.php file, and applying input validation or sanitization to the 'lang' parameter to prevent directory traversal sequences such as '../'. If a patch or updated version of YouPHPTube is available that fixes this vulnerability, it should be applied promptly. Additionally, consider implementing web application firewall (WAF) rules to block requests containing suspicious directory traversal patterns in the 'lang' parameter. Disabling or restricting access to unnecessary PHP files that could be included via this vulnerability can also reduce risk. [2, 3]
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows unauthenticated attackers to access arbitrary files on the server, potentially exposing sensitive data. This exposure of confidential information could lead to non-compliance with data protection regulations such as GDPR and HIPAA, which require safeguarding personal and sensitive data against unauthorized access. Therefore, exploitation of this vulnerability may result in violations of these standards due to compromised confidentiality. [2, 3]