# 🔒 Security Vulnerability Analysis — posterg-website

> **Date:** 2026-02-08  
> **Scope:** Full static code review of all PHP, nginx config, and deployment files.  
> **Analyst:** Claude Code

---

## Good Practices Already in Place

- ✅ SQL injection: all queries use PDO prepared statements consistently
- ✅ XSS output: `htmlspecialchars()` applied on all user-controlled output
- ✅ CSRF: tokens generated with `bin2hex(random_bytes(32))` and validated with `hash_equals()` (timing-safe) on all state-changing forms
- ✅ File upload: MIME type validated with `finfo` for cover images and thesis files
- ✅ Input validation: year, IDs, and pagination values cast to integers
- ✅ LIKE wildcard escaping implemented in public search (`Database::escapeLikeString`)

---

## 🔴 CRITICAL

### 1. Admin HTTP Basic Auth Over Plain HTTP (No TLS/HTTPS)

**File:** `nginx/posterg.conf`

The nginx config listens only on port 80. HTTP Basic Authentication Base64-encodes
credentials but **does not encrypt them**. Anyone intercepting network traffic can
decode the admin password trivially (`echo "dXNlcjpwYXNz" | base64 -d`).

```nginx
listen 80 default_server;   # ← No HTTPS configured at all
auth_basic "Admin Access - Post-ERG";
auth_basic_user_file /etc/nginx/.htpasswd-posterg;
```

**Fix:** Add a TLS/HTTPS server block (e.g., Let's Encrypt via certbot) and redirect
all port 80 traffic to HTTPS:

```nginx
server {
    listen 80;
    return 301 https://$host$request_uri;
}
server {
    listen 443 ssl;
    ssl_certificate /etc/letsencrypt/live/posterg.erg.be/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/posterg.erg.be/privkey.pem;
    # ... rest of config
}
```

---

### 2. No PHP-Level Authentication in Admin Panel

**Files:** `public/admin/index.php`, `add.php`, `edit.php`, `import.php`, `thanks.php`

Every admin file calls `session_start()` only to generate a CSRF token. There is
**zero check that the user is authenticated in PHP**. If nginx is misconfigured,
restarted, or the app is accessed directly without nginx in front (e.g., via the
PHP CLI dev server), all admin functionality is fully open.

```php
session_start();
if (empty($_SESSION['csrf_token'])) {
    $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
}
// ← No authentication check whatsoever
```

**Fix:** Implement a PHP login system with session-based authentication and add an
auth guard at the top of every admin page:

```php
// public/admin/auth.php
session_start();
if (empty($_SESSION['admin_authenticated'])) {
    header('Location: /admin/login.php');
    exit;
}
```

---

## 🟠 HIGH

### 3. Uploaded Files Stored Inside the Webroot

**File:** `public/admin/actions/formulaire.php` (lines ~127–131)

Thesis files and cover images are stored *inside* the public web directory:

```php
$uploadBaseDir = __DIR__ . "/data/theses/{$annee}/{$identifier}/";
$coverDir      = __DIR__ . "/data/covers/";
// Resolves to: /var/www/posterg/public/admin/actions/data/...
```

This means uploaded PDFs, ZIPs, MP4s, and images sit in a potentially web-accessible
path. The nginx rule `location ^~ /data/ { deny all; }` only blocks the URL path
`/data/…` from the server root — it does **not** block `/admin/actions/data/…`.

**Fix:** Store uploads outside the webroot and serve through a controller:

```php
$uploadBaseDir = '/var/www/posterg/storage/theses/' . $annee . '/' . $identifier . '/';
$coverDir      = '/var/www/posterg/storage/covers/';
```

---

### 4. File Path Mismatch — Media Files Cannot Be Served to Public

**Files:** `formulaire.php` (stores), `memoire.php` and `search.php` (reference)

Files are stored at `public/admin/actions/data/theses/YEAR/ID/file.ext` but recorded
in the database as `data/theses/YEAR/ID/file.ext`. When a browser loads `/memoire.php`,
relative links resolve to `/data/theses/…`, which nginx blocks:

```php
// memoire.php — tries to embed a URL that nginx denies
<embed src="<?= htmlspecialchars($file['file_path']); ?>" type="application/pdf">
```

```nginx
location ^~ /data/ {
    deny all;   # ← This kills the public file references
}
```

This is both a security misconfiguration and a **functional bug** (files never display
on the public site).

**Fix:** Use a consistent, intentionally accessible path (e.g., `/var/www/posterg/storage/`)
and serve files through a dedicated PHP endpoint that validates access rights.

---

### 5. Rate Limiter Vulnerable to IP Spoofing

**File:** `src/RateLimit.php` — method `getClientIdentifier()`

```php
if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];  // ← Fully attacker-controlled
} elseif (!empty($_SERVER['HTTP_CLIENT_IP'])) {
    $ip = $_SERVER['HTTP_CLIENT_IP'];         // ← Also attacker-controlled
}
```

Any attacker can set `X-Forwarded-For: 1.2.3.4` to a new IP on every request,
completely bypassing the rate limiter. The `/search` endpoint has no other
brute-force protection.

**Fix:** Use `$_SERVER['REMOTE_ADDR']` only. If behind a trusted reverse proxy,
whitelist the proxy and extract the last trusted IP from the forwarded header:

```php
private function getClientIdentifier(): string {
    // Only trust REMOTE_ADDR unless explicitly behind a known proxy
    return $_SERVER['REMOTE_ADDR'] ?? 'unknown';
}
```

---

### 6. `.htaccess` Security Controls Silently Ignored by nginx

**File:** `public/admin/.htaccess`

This file contains X-Frame-Options, CSP, X-Content-Type-Options, `Options -Indexes`,
and file-protection rules — all **Apache-specific directives**. The production server
runs nginx, which never reads `.htaccess`. None of these controls are active.

```apache
Header always set Content-Security-Policy "..."   # ← Dead letter on nginx
Options -Indexes                                   # ← Never applied
<FilesMatch "(error\.log)$">                       # ← nginx doesn't parse this
    Require all denied
```

**Fix:** Move all security rules into the nginx `server` block directly.

---

## 🟡 MEDIUM

### 7. LIKE Wildcard Injection in Admin Search

**File:** `public/admin/index.php` (lines ~38–42)

```php
$searchParam = "%$searchQuery%";  // ← % and _ characters not escaped
$params[] = $searchParam;
```

While SQL injection is prevented by prepared statements, unescaped `%` and `_`
trigger unintended SQL wildcard matching (e.g., `%` matches every row, `_` matches
any single character). The public `Database::searchTheses()` already does this
correctly — the admin search does not.

**Fix:**
```php
$escaped = str_replace(['\\', '%', '_'], ['\\\\', '\\%', '\\_'], $searchQuery);
$searchParam = "%" . $escaped . "%";
```

---

### 8. Session Cookies Not Hardened

**Files:** All admin PHP files using `session_start()`

No secure cookie parameters are configured before `session_start()`:

- No `Secure` flag → cookies sent over plain HTTP
- No `HttpOnly` flag → accessible to JavaScript (XSS cookie theft)
- No `SameSite` → vulnerable to cross-site request forgery via cookies

**Fix:** Add before every `session_start()`:

```php
session_set_cookie_params([
    'lifetime' => 0,
    'path'     => '/admin',
    'secure'   => true,
    'httponly' => true,
    'samesite' => 'Strict',
]);
session_start();
```

---

### 9. Error Log in Potentially Web-Accessible Path

**File:** `public/admin/actions/formulaire.php`

```php
ini_set('error_log', 'error.log');  // Relative path → public/admin/actions/error.log
```

The nginx config denies `.md`, `.txt`, `.sql`, `.sh`, `.json` files — but **not
`.log` files**. The `.htaccess` rule blocking `error.log` is ignored by nginx (see #6).
Error logs can contain PHP stack traces, internal file paths, and database details.

**Fix:** Use an absolute path outside the webroot:

```php
ini_set('error_log', '/var/log/posterg/error.log');
```

---

### 10. External CDN Stylesheet Without Subresource Integrity (SRI)

**File:** `public/admin/inc/head.php`

```html
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/water.css@2/out/water.css">
```

If the CDN is compromised, attackers can inject malicious CSS into the admin panel.
CSS-based data exfiltration (capturing form inputs via attribute selectors) is a
known attack vector.

**Fix:** Pin the resource with an integrity hash:

```html
<link rel="stylesheet"
      href="https://cdn.jsdelivr.net/npm/water.css@2/out/water.css"
      integrity="sha256-<computed-hash>"
      crossorigin="anonymous">
```

Generate the hash: `curl -s https://cdn.jsdelivr.net/npm/water.css@2/out/water.css | openssl dgst -sha256 -binary | base64`

---

### 11. Missing Content Security Policy on Public Pages

**File:** `nginx/posterg.conf`

The nginx config sets `X-Frame-Options`, `X-Content-Type-Options`, etc., but defines
**no `Content-Security-Policy`** header for public routes. This leaves the public
site without a last line of defence if any output escaping is ever missed.

**Fix:** Add to the main `server` block in nginx:

```nginx
add_header Content-Security-Policy
    "default-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; object-src 'none'; frame-ancestors 'none';"
    always;
```

---

### 12. CSV Import Without Server-Side MIME Validation

**File:** `public/admin/import.php`

The cover image upload validates MIME type with `finfo`, but the CSV upload does not:

```php
// Only HTML-side restriction — trivially bypassed:
<input type="file" id="csv_file" name="csv_file" accept=".csv" required>
```

**Fix:**
```php
$finfo = new finfo(FILEINFO_MIME_TYPE);
$mime  = $finfo->file($_FILES['csv_file']['tmp_name']);
if (!in_array($mime, ['text/plain', 'text/csv', 'application/csv'])) {
    throw new Exception("Type de fichier invalide. Seuls les fichiers CSV sont acceptés.");
}
```

---

## 🔵 LOW

### 13. Deprecated `X-XSS-Protection` Header

**Files:** `nginx/posterg.conf`, `public/admin/.htaccess`

`X-XSS-Protection "1; mode=block"` has been removed from Chrome and is ignored by
Firefox. In some legacy browsers it can actually *introduce* reflected-XSS
vulnerabilities by blocking legitimate content.

**Fix:** Remove the header. Rely on a properly configured CSP instead.

---

### 14. Missing `rel="noreferrer"` on External Links

**File:** `public/admin/thanks.php`

```php
<a href="..." target="_blank" rel="noopener">
```

`noopener` prevents `window.opener` hijacking, but `noreferrer` is also needed to
prevent the internal admin URL from leaking in the HTTP `Referer` header to external
sites.

**Fix:** Use `rel="noopener noreferrer"` on all `target="_blank"` links.

---

### 15. Unescaped Integer Outputs (Cosmetic / Defence in Depth)

**Files:** `public/index.php`, `public/search.php`

```php
<?= $item["id"] ?>     // integer from DB
<?= $year; ?>          // integer from DB
<?= $totalItems; ?>    // integer from COUNT()
```

Safe in practice (integers cannot carry XSS payloads), but inconsistent with the
rest of the codebase which uses `htmlspecialchars()` everywhere.

**Fix:** Apply explicit integer cast for clarity: `<?= (int) $item['id'] ?>`.

---

### 16. Redundant `DATABASE_PATH` Constant

**File:** `config/bootstrap.php`

```php
define('DATABASE_PATH', APP_ROOT . '/storage/test.db');
```

This constant is never used anywhere. `Database.php` uses `getDatabasePath()` from
`src/config.php`. The duplicate creates confusion about which configuration is
authoritative and could lead to future bugs if someone uses the wrong one.

**Fix:** Remove the `DATABASE_PATH` define from `bootstrap.php`.

---

## Summary Table

| # | Issue | Severity | File(s) |
|---|-------|----------|---------|
| 1 | No HTTPS — admin credentials exposed in transit | 🔴 CRITICAL | nginx/posterg.conf |
| 2 | No PHP-level authentication in admin | 🔴 CRITICAL | public/admin/\*.php |
| 3 | Uploaded files stored inside webroot | 🟠 HIGH | admin/actions/formulaire.php |
| 4 | File path mismatch — media broken & insecure | 🟠 HIGH | formulaire.php, memoire.php |
| 5 | Rate limiter bypassed by IP spoofing | 🟠 HIGH | lib/RateLimit.php |
| 6 | .htaccess rules ignored by nginx | 🟠 HIGH | public/admin/.htaccess |
| 7 | LIKE wildcard injection in admin search | 🟡 MEDIUM | public/admin/index.php |
| 8 | Session cookies not hardened | 🟡 MEDIUM | All admin PHP files |
| 9 | error.log in web-accessible path | 🟡 MEDIUM | admin/actions/formulaire.php |
| 10 | CDN stylesheet without SRI | 🟡 MEDIUM | admin/inc/head.php |
| 11 | Missing CSP on public pages | 🟡 MEDIUM | nginx/posterg.conf |
| 12 | CSV upload missing MIME validation | 🟡 MEDIUM | admin/import.php |
| 13 | Deprecated X-XSS-Protection header | 🔵 LOW | nginx/posterg.conf |
| 14 | Missing rel="noreferrer" on external links | 🔵 LOW | admin/thanks.php |
| 15 | Unescaped integers (defence in depth) | 🔵 LOW | index.php, search.php |
| 16 | Redundant DATABASE_PATH constant | 🔵 LOW | config/bootstrap.php |

---

*End of report.*