CVE-2025-25257 Detection Engineering Repository

Overview

This repository provides production-ready detection engineering content for CVE-2025-25257, a pre-authentication SQL Injection vulnerability in Fortinet FortiWeb Fabric Connector versions 7.0 through 7.6.x. Successful exploitation can lead to Remote Code Execution without any prior authentication.

This content is intended for defensive use only. It is scoped for Security Operations Centre (SOC) teams, detection engineers, and threat hunters. No weaponised exploit code is included.

Vulnerability Summary

Vulnerability Description

CVE-2025-25257 affects the Fabric Connector API endpoint /api/fabric/device/status in FortiWeb. The Authorization header is passed directly into a SQL query without sanitisation. An unauthenticated attacker can inject SQL syntax into the Bearer token value to manipulate the underlying query, bypass authentication, and in certain configurations achieve Remote Code Execution through SQL-based command stacking or file write primitives.

The vulnerability is exploitable over the network with no credentials. It is trivially detectable in HTTP access logs if log collection is in place.

Exploitation Method

The attacker sends a crafted HTTP GET request to the Fabric Connector API. The Bearer token in the Authorization header contains injected SQL. Example pattern:

Authorization: Bearer aaa' OR '1'='1

This causes the backend SQL query to evaluate as true, bypassing token validation. Further exploitation may involve UNION-based injection to read data or stacked queries to write files or execute OS commands depending on the database configuration and privileges.

Example PoC Payload (Reference Only)

The following is documented for detection rule validation purposes only.

GET /api/fabric/device/status HTTP/1.1
Host: <fortiweb-ip>
Authorization: Bearer aaa' OR '1'='1

Detection rules in this repository are tuned to identify this and similar injection patterns in HTTP logs and network traffic.

Detection Coverage Table

YARA Rules

YARA rules are located in rules/yara/.

Files

• cve_2025_25257_http.yar - Detects exploitation patterns in HTTP log files and captured traffic
• cve_2025_25257_webshell.yar - Detects web shells potentially dropped post-exploitation
• cve_2025_25257_payload.yar - Detects raw payload artifacts on disk

Usage

Scan HTTP access logs:

yara -r rules/yara/cve_2025_25257_http.yar /var/log/fortiweb/

Scan web root for dropped files:

yara -r rules/yara/cve_2025_25257_webshell.yar /var/www/html/

Scan captured PCAP:

yara rules/yara/cve_2025_25257_http.yar capture.pcap

Run all rules recursively against a directory:

yara -r rules/yara/ /path/to/scan/

KQL Queries

KQL queries are located in rules/kql/. Each file targets a specific detection category.

Sigma Rules

Sigma rules are in rules/sigma/. These can be converted to any SIEM format using sigma-cli or pySigma.

Convert to Splunk SPL:

sigma convert -t splunk rules/sigma/cve_2025_25257_sqli.yml

Convert to Elastic EQL:

sigma convert -t elasticsearch rules/sigma/cve_2025_25257_sqli.yml

Testing Instructions

Verify Affected Version

On the FortiWeb appliance CLI:

get system status | grep Version

Affected: 7.0.x through 7.6.0 Patched: 7.6.1 and later

Docker Lab Setup

A basic Nginx reverse proxy simulating the vulnerable endpoint can be used for detection testing. No actual FortiWeb image is required for log-based detection validation.

# Pull the test lab container
docker run -d \
  --name fortiweb-sim \
  -p 8443:443 \
  -v $(pwd)/src/lab/nginx.conf:/etc/nginx/nginx.conf:ro \
  nginx:alpine

# Send a simulated exploitation request
curl -k -H "Authorization: Bearer aaa' OR '1'='1" \
  https://localhost:8443/api/fabric/device/status

This will generate an access log entry matching the detection patterns in D-01.

Verify Detection Triggers

After sending the test request, check the simulated log output:

docker logs fortiweb-sim | grep "fabric/device/status"

Expected log entry pattern:

"GET /api/fabric/device/status HTTP/1.1" 401 - "Bearer aaa' OR '1'='1"

Run the YARA rule against the log:

yara rules/yara/cve_2025_25257_http.yar /var/log/nginx/access.log

Expected output:

CVE_2025_25257_SQLi_AuthHeader /var/log/nginx/access.log

Repository Structure

cve-2025-25257-detection/
├── README.md
├── LICENSE
├── .gitignore
├── rules/
│   ├── yara/
│   │   ├── cve_2025_25257_http.yar
│   │   ├── cve_2025_25257_webshell.yar
│   │   └── cve_2025_25257_payload.yar
│   ├── kql/
│   │   ├── 01_web_exploitation.kql
│   │   ├── 02_process_spawn.kql
│   │   ├── 03_command_execution.kql
│   │   ├── 04_file_creation.kql
│   │   ├── 05_persistence.kql
│   │   ├── 06_config_modification.kql
│   │   └── 07_threat_hunting.kql
│   ├── sigma/
│   │   ├── cve_2025_25257_sqli.yml
│   │   └── cve_2025_25257_process_spawn.yml
│   └── splunk/
│       ├── web_exploitation.spl
│       └── process_anomaly.spl
├── docs/
│   ├── iocs.md
│   ├── mitre_attack.md
│   └── false_positive_analysis.md
├── src/
│   ├── poc.py
│   └── lab/
│       └── nginx.conf
└── sysmon/
    └── sysmon_config_snippet.xml

References

• FortiWeb Security Advisory FG-IR-25-007
• ExploitDB Entry 52473
• MITRE ATT&CK T1190 - Exploit Public-Facing Application
• OWASP SQL Injection
• Fortinet PSIRT Advisory Portal

Credits

• Vulnerability Discovery and PoC: Milad Karimi (Ex3ptionaL), [email protected]
• Detection Engineering: This repository
• MITRE ATT&CK Framework: MITRE Corporation

Disclaimer

This repository is provided for defensive and educational purposes only. All detection content is intended to help security teams identify and respond to exploitation attempts. Do not use any content in this repository against systems you do not own or have explicit written permission to test.

License

This project is licensed under the MIT License. See LICENSE for details.