MobileDetect is a popular PHP library used to detect mobile devices and tailor content accordingly. Because it’s often embedded into demos, dashboards, and internal tools, security issues inside its example code can quietly turn into real attack surfaces.
An example of this is CVE-2018-25080, which is a cross-site scripting (XSS) vulnerability related to MobileDetect deployments that expose the affected example files.
MobileDetect Vulnerability Summary
1. MobileDetect Project.
2. MobileDetect 2.8.31 (4da80e5 commit) has been identified as vulnerable to CVE-2018-25080.
3. Vulnerability Type Cross Site Scripting (XSS) found on Windows OS.
4. CodeSecLab reported this issue.
The vulnerability occurs because the user provides data to session_example.php as input, which does not have sanitization and encoding applied to it before being returned back to the user on their web page.
What is the issue?
The example script takes parts of the request path and puts them right into the response without applying any filtering so an attacker can put in their own JavaScript to run on the browser of the victim.
The filename of the file is often called 'example' and is frequently accessible for the purpose of providing an actual demonstration of how to deploy at the time development/testing occurs. However, it is still accessible to everyone to utilize while working in that environment or during the internal testing on it.
Proof of Concept (PoC)
The problem is triggered by sending only a single GET request that has been crafted correctly:
GET /examples/session_example.php/"><script>alert(document.domain)</script>
Once you have been able to load and view the example files within MobileDetect using the browser you will find that the scripting injected into these vulnerable endpoints will work directly when visiting them via your browser to demonstrate it is XSS and does not require any advanced techniques to bypass the method used. This can be classed as a straightforward Reflected XSS attack without excessive complexity.
Steps to recreate
1. Ensure you are able to access the example files from the examples folder of MobileDetect
2. Send a malicious payload via the URL to the vulnerable endpoint
3. You will see the scripting execute in your browser context.
Impact
If this endpoint can be accessed by other users it allows, but is not limited to: session hijacking, theft of credentials, forced actions on behalf of authenticated users and injection of malicious content into trusted Web Pages. It is particularly dangerous in situations where examples files are in the same domain as the production application.
Why This Matters
Example files are often overlooked in security reviews, but they are actively sought after by attackers. An exposed demo script can be the difference between a secure application and an insecure one.
This issue reinforces a common lesson; anything accessible via HTTP should be treated as if it were production code.
Mitigation Recommendations
1. Remove the examples directory from production environments
2. limit demo file access during development
3. use strict output encoding when reflecting user input
4. audit third-party libraries for exposed example endpoints.
Source: Exploit DB
