fix(scanner): avoid SVG/XML false positives; add allowlist and .gitignore

Relax payload scanner for XML/SVG by passing content-type into checks
Skip JS-style eval() detection when content-type is XML/SVG
Pass request Content-Type through sniff_file_for_php_payload() and raw-body checks
Add common XML/SVG content-types to allowlist.json
Add repository .gitignore (ignore logs, quarantine/, state/, env, vendor, IDE files)
This commit is contained in:
2026-02-07 15:11:15 +01:00
commit 037b176892
5 changed files with 1585 additions and 0 deletions

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# Upload Logger repository .gitignore
# Runtime logs and quarantine/state directories (do not commit)
/logs/
/quarantine/
/state/
*.log
uploads.log
# Peek allow marker (local only)
/.upload_logger_allow_peek
# Local environment files
.env
.env.*
# Composer / vendor
/vendor/
/composer.lock
# Node
/node_modules/
# IDEs and OS files
.vscode/
.idea/
*.iml
.DS_Store
Thumbs.db
# Temp/cache
*.cache
*.tmp

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# 🔐 Per-Site PHP Upload Guard Integration Guide
This guide explains how to integrate a global PHP upload monitoring script
using `auto_prepend_file`, on a **per-site basis**, with isolated security
folders.
---
## 📁 1. Recommended Folder Structure
Each website should contain its own hidden security directory:
```
/var/www/sites/example-site/
├── public/
├── app/
├── uploads/
├── .security/
│ ├── upload_guard.php
│ └── logs/
│ └── uploads.log
````
Benefits:
- Per-site isolation
- Easier debugging
- Independent log files
- Reduced attack surface
---
## 🔧 2. Create the Security Directory
From the site root:
```bash
cd /var/www/sites/example-site
mkdir .security
mkdir .security/logs
````
Set secure permissions:
```bash
chown -R root:www-data .security
chmod 750 .security
chmod 750 .security/logs
```
---
## 📄 3. Install the Upload Guard Script
Create the script file:
```bash
nano .security/upload_guard.php
```
Paste your hardened upload monitoring script.
Inside the script, configure logging:
```php
$logFile = __DIR__ . '/logs/uploads.log';
```
Lock the script:
```bash
chown root:root .security/upload_guard.php
chmod 644 .security/upload_guard.php
```
---
## ⚙️ 4. Enable auto_prepend_file (Per Site)
### Option A — PHP-FPM Pool (Recommended)
Edit the sites PHP-FPM pool configuration:
```bash
nano /etc/php/8.x/fpm/pool.d/example-site.conf
```
Add:
```ini
php_admin_value[auto_prepend_file] = /var/www/sites/example-site/.security/upload_guard.php
```
Reload PHP-FPM:
```bash
systemctl reload php8.x-fpm
```
# 🔐 Per-Site PHP Upload Guard Integration Guide
This guide explains how to integrate a global PHP upload monitoring script
using `auto_prepend_file`, on a **per-site basis**, with isolated security
folders.
---
## 📁 1. Recommended Folder Structure
Each website should contain its own hidden security directory:
```text
/var/www/sites/example-site/
├── public/
├── app/
├── uploads/
├── .security/
│ ├── upload-logger.php
│ └── logs/
│ └── uploads.log
```
Benefits:
- Per-site isolation
- Easier debugging
- Independent log files
- Reduced attack surface
---
## 🔧 2. Create the Security Directory
From the site root:
```bash
cd /var/www/sites/example-site
mkdir .security
mkdir .security/logs
```
Set secure permissions:
```bash
chown -R root:www-data .security
chmod 750 .security
chmod 750 .security/logs
```
---
## 📄 3. Install the Upload Guard Script
Create the script file:
```bash
nano .security/upload-logger.php
```
Paste your hardened upload monitoring script.
Inside the script, configure logging:
```php
$logFile = __DIR__ . '/logs/uploads.log';
```
Lock the script:
```bash
chown root:root .security/upload-logger.php
chmod 644 .security/upload-logger.php
```
---
## ⚙️ 4. Enable auto_prepend_file (Per Site)
### Option A — PHP-FPM Pool (Recommended)
Edit the sites PHP-FPM pool configuration:
```bash
nano /etc/php/8.x/fpm/pool.d/example-site.conf
```
Add:
```ini
php_admin_value[auto_prepend_file] = /var/www/sites/example-site/.security/upload-logger.php
```
Reload PHP-FPM (adjust service name to match your PHP version):
```bash
systemctl reload php8.x-fpm
```
---
### Option B — Apache Virtual Host
If using a shared PHP-FPM pool, configure in the vHost:
```apache
<Directory /var/www/sites/example-site>
php_admin_value auto_prepend_file /var/www/sites/example-site/.security/upload-logger.php
</Directory>
```
Reload Apache:
```bash
systemctl reload apache2
```
---
## 🚫 5. Block Web Access to `.security`
Prevent direct HTTP access to the security folder.
In the vHost:
```apache
<Directory /var/www/sites/example-site/.security>
Require all denied
</Directory>
```
Or in `.htaccess` (if allowed):
```apache
Require all denied
```
---
## ✅ 6. Verify Installation
Create a temporary file:
```php
<?php phpinfo();
```
Open it in browser and search for:
```text
auto_prepend_file
```
Expected output:
```text
/var/www/sites/example-site/.security/upload_guard.php
```
Remove the test file after verification.
---
## 🧪 7. Test Upload Logging
Create a simple upload test:
```php
<form method="post" enctype="multipart/form-data">
<input type="file" name="testfile">
<button>Upload</button>
</form>
```
Upload any file and check logs:
```bash
cat .security/logs/uploads.log
```
You should see a new entry.
---
## 🔒 8. Disable PHP Execution in Uploads
Always block PHP execution in upload directories.
Example (Apache):
```apache
<Directory /var/www/sites/example-site/uploads>
php_admin_flag engine off
AllowOverride None
</Directory>
```
Reload Apache after changes.
---
## 🛡️ 9. Enable Blocking Mode (Optional)
After monitoring for some time, enable blocking.
Edit:
```php
$BLOCK_SUSPICIOUS = true;
```
Then reload PHP-FPM.
---
## 📊 10. (Optional) Fail2Ban Integration (JSON logs)
Create a JSON-aware filter that matches `event: "suspicious"` and extracts the IP address.
```bash
nano /etc/fail2ban/filter.d/php-upload.conf
```
```ini
[Definition]
# Match JSON lines where event == "suspicious" and capture the IPv4 address as <HOST>
failregex = ^.*"event"\s*:\s*"suspicious".*"ip"\s*:\s*"(?P<host>\d{1,3}(?:\.\d{1,3}){3})".*$
ignoreregex =
```
Create a jail that points to the per-site logs (or a central aggregated log):
```ini
[php-upload]
enabled = true
filter = php-upload
logpath = /var/www/sites/*/.security/logs/uploads.log
maxretry = 3
findtime = 600
bantime = 86400
action = iptables-multiport[name=php-upload, port="http,https", protocol=tcp]
```
Restart Fail2Ban:
```bash
systemctl restart fail2ban
```
### Fail2Ban action: nftables example
If your host uses nftables, prefer the `nftables` action so bans use the system firewall:
```ini
[php-upload]
enabled = true
filter = php-upload
logpath = /var/www/sites/*/.security/logs/uploads.log
maxretry = 3
findtime = 600
bantime = 86400
action = nftables[name=php-upload, port="http,https", protocol=tcp]
```
This uses Fail2Ban's `nftables` action (available on modern distributions). Adjust `port`/`protocol` to match your services.
### Central log aggregation (Filebeat / rsyslog)
Forwarding per-site JSON logs to a central collector simplifies alerts and Fail2Ban at scale. Two lightweight options:
- Filebeat prospector (send to Logstash/Elasticsearch):
```yaml
filebeat.inputs:
- type: log
paths:
- /var/www/sites/*/.security/logs/uploads.log
json.keys_under_root: true
json.add_error_key: true
fields:
source: php-upload-logger
output.logstash:
hosts: ["logserver:5044"]
```
- rsyslog `imfile` forwarding to remote syslog (central rsyslog/logstash):
Add to `/etc/rsyslog.d/10-upload-logger.conf`:
```text
module(load="imfile" PollingInterval="10")
input(type="imfile" File="/var/www/sites/*/.security/logs/uploads.log" Tag="uploadlogger" Severity="info" Facility="local7")
*.* @@logserver:514
```
Both options keep JSON intact for downstream parsing and reduce per-host Fail2Ban complexity.
### Testing your Fail2Ban filter
Create a temporary file containing a representative JSON log line emitted by `upload-logger.php` and run `fail2ban-regex` against your filter to validate detection.
```bash
# create test file with a suspicious event
cat > /tmp/test_upload.log <<'JSON'
{"ts":"$(date -u +%Y-%m-%dT%H:%M:%SZ)","event":"suspicious","ip":"1.2.3.4","user":"guest","name":"evil.php.jpg","real_mime":"application/x-php","reasons":["bad_name","php_payload"]}
JSON
# test the filter (adjust path to filter if different)
fail2ban-regex /tmp/test_upload.log /etc/fail2ban/filter.d/php-upload.conf
```
`fail2ban-regex` will report how many matches were found and display sample matched groups (including the captured `<HOST>`). Use this to iterate on the `failregex` if it doesn't extract the IP as expected.
---
## 🏁 Final Architecture
```text
Client → Web Server → PHP (auto_prepend) → Application → Disk
Log / Alert / Ban
```
This provides multi-layer upload monitoring and protection.
---
## 🗂️ Log rotation & SELinux/AppArmor notes
- Example `logrotate` snippet to rotate per-site logs weekly and keep 8 rotations:
```text
/var/www/sites/*/.security/logs/uploads.log {
weekly
rotate 8
compress
missingok
notifempty
create 0640 root adm
}
```
- If your host enforces SELinux or AppArmor, ensure the `.security` directory and log files have the correct context so PHP-FPM can read the script and write logs. For SELinux (RHEL/CentOS) you may need:
```bash
chcon -R -t httpd_sys_rw_content_t /var/www/sites/example-site/.security/logs
restorecon -R /var/www/sites/example-site/.security
```
Adjust commands to match your platform and policy. AppArmor profiles may require adding paths to the PHP-FPM profile.
## ⚠️ Security Notes
- Never use `777` permissions
- Keep `.security` owned by `root`
- Regularly review logs
- Update PHP and extensions
- Combine with OS-level auditing for best results
---
## 📌 Recommended Maintenance
Weekly:
```bash
grep ALERT .security/logs/uploads.log
```

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# Upload Logger (Hardened v3)
This repository contains the v3 upload-logging helper: a hardened single-file monitor that logs uploads, detects common evasion techniques, and optionally blocks suspicious uploads.
Primary file: [upload-logger.php](upload-logger.php)
Summary
- Purpose: Log normal uploads and raw-body uploads, detect double-extension tricks, fake images, PHP payloads embedded in files, and provide flood detection.
- Runs only for HTTP requests; recommended to enable via `auto_prepend_file` in a per-site PHP-FPM pool for broad coverage.
Key configuration (top of `upload-logger.php`)
- `$logFile` — path to the log file (default: `__DIR__ . '/logs/uploads.log'`).
- `$BLOCK_SUSPICIOUS` — if `true` the script returns `403` and exits when suspicious uploads are detected.
- `$MAX_SIZE` — threshold for `WARN big_upload` (default 50 MB).
- `$RAW_BODY_MIN` — minimum raw request body size considered suspicious when `$_FILES` is empty (default 500 KB).
- `$FLOOD_WINDOW_SEC`, `$FLOOD_MAX_UPLOADS` — lightweight per-IP flood detection window and max uploads before alerting.
- `$SNIFF_MAX_BYTES`, `$SNIFF_MAX_FILESIZE` — parameters controlling fast content sniffing for PHP/webshell markers.
- `$LOG_USER_AGENT` — include `User-Agent` in logs when true.
What it detects
- Dangerous filenames (path-traversal, double extensions, hidden php-like dotfiles).
- Fake images: file extension indicates an image but `finfo` returns a non-image MIME.
- PHP/webshell markers inside file content (fast head-scan up to configured limits).
- Archive uploads (`.zip`, `.tar`, etc.) flagged for attention.
- Raw request bodies (e.g., `application/octet-stream` or streamed uploads) when `$_FILES` is empty and body size exceeds `$RAW_BODY_MIN`.
- Flooding by counting uploads per-IP in a rolling window.
Logging and alerts
- Each accepted upload generates an `UPLOAD` line with fields: `ip`, `user`, `name`, `size`, `type`, `real` (detected MIME), `tmp`, `uri`, and optional `ua`.
- Suspicious uploads generate `ALERT suspicious` entries with `reasons=` listing detected flags (e.g., `bad_name,fake_image,php_payload`).
- Other notes: `WARN big_upload`, `NOTE archive_upload`, `MULTIPART_NO_FILES`, and `RAW_BODY` are emitted when appropriate.
Integration notes
- Preferred deployment: set `php_admin_value[auto_prepend_file]` in the site-specific PHP-FPM pool to the absolute path of `upload-logger.php` so it runs before application code.
- If using sessions for user identification, the script safely reads `$_SESSION['user_id']` only when a session is active; do not rely on it being present unless your app starts sessions earlier.
- The script uses `is_uploaded_file()`/`finfo` where available; ensure the PHP `fileinfo` extension is enabled for best MIME detection.
Operational recommendations
- Place the `logs/` directory outside the webroot or deny web access to it.
- Ensure correct owner/group and permissions (e.g., owner `root`, group `www-data`, `chmod 750` on `.security` and `chmod 640` for logs) and confirm PHP-FPM's user/group membership.
- Rotate logs with `logrotate` (see `INTEGRATION.md` for an example snippet).
- If your host uses SELinux/AppArmor, set correct contexts or adjust profiles so PHP-FPM can read the script and write logs.
Limitations & safety
- This script improves visibility and blocks common upload tricks but cannot guarantee interception of every file-write vector (e.g., direct application writes, ZipArchive extraction, custom file APIs). Use it as part of a layered defense.
- Content sniffing is limited to a head-scan to reduce CPU and false positives; tune `$SNIFF_MAX_BYTES` and `$SNIFF_MAX_FILESIZE` to balance coverage and performance.
Quick start
1. Place `upload-logger.php` in a per-site secure folder (see `INTEGRATION.md`).
2. Ensure the `logs/` directory exists and is writable by PHP-FPM.
3. Enable as an `auto_prepend_file` in the site pool and reload PHP-FPM.
4. Monitor `logs/uploads.log` and adjust configuration options at the top of the script.
Support & changes
- For changes, edit configuration variables at the top of `upload-logger.php` or adapt detection helpers as needed.
---
Generated for upload-logger.php (v3).

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{
"uris": [
"/api/uploads/avatars",
"/api/v1/avatars",
"/user/avatar",
"/media/upload",
"/api/media",
"/api/uploads",
"/api/v1/uploads",
"/attachments/upload",
"/upload",
"#^/internal/webhook#",
"#/hooks/(github|gitlab|stripe|slack)#",
"/services/avatars",
"/api/profile/photo"
],
"ctypes": [
"image/svg+xml",
"application/xml",
"text/xml"
]
}

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