CVE-2025-20393

📌 Overview

CVE-2025-20393 is a critical Remote Command Execution (RCE) vulnerability affecting Cisco Secure Email Gateway (SEG) and Cisco Secure Email and Web Manager (SEWM) appliances running Cisco AsyncOS.

The vulnerability exists due to improper input validation in the Spam Quarantine feature. An unauthenticated remote attacker can exploit this flaw by sending crafted HTTP requests, leading to arbitrary command execution with root privileges.

This vulnerability is considered extremely dangerous because:

• No authentication is required
• Exploitation happens over the network
• Complete system compromise is possible
• Active exploitation has been observed in the wild

🎯 Impact

• Full root-level access
• Ability to execute arbitrary system commands
• Potential data exfiltration
• Persistent backdoor installation
• Email infrastructure compromise

CVSS Score: 10.0 (Critical)

🧩 Affected Products & Versions

The following Cisco products are affected if the Spam Quarantine feature is enabled and exposed:

Affected Products

• Cisco Secure Email Gateway (SEG)
• Cisco Secure Email and Web Manager (SEWM)

Affected Versions

• All Cisco AsyncOS versions where:
  • Spam Quarantine is enabled
  • Interface is accessible over the internet

✅ Cisco cloud-hosted email security services are NOT affected.

🛠 Patch & Mitigation Status

Recommended Mitigations

• Disable Spam Quarantine if not required
• Restrict access using firewall rules
• Do not expose management interfaces to the internet
• Place the appliance behind VPN or internal network
• Monitor HTTP logs for suspicious requests
• Rebuild appliance if compromise is suspected

🔍 Search Dorks

🌐 Google Dorks

intitle:"Cisco Secure Email Gateway"

inurl:"/spamquarantine" "Cisco"

🕵️ Shodan Dorks

product:"IronPort AsyncOS http config"

product:"Cisco Secure Email Gateway"

http.title:"Cisco Secure Email"

🦊 FOFA Dorks

app="Cisco Secure Email Gateway"

title="Cisco Secure Email"

🔎 Hunter Dorks

product.name="Cisco Email Security Appliance"

title:"Cisco Secure Email"

body:"Cisco AsyncOS"

🌍 ZoomEye Dorks

app="Cisco Secure Email Platform"

device:"Cisco Secure Email"

http.html_title:"Cisco Secure Email Gateway"

🚀 How to Use

1️⃣ Clone the Repository

git clone https://github.com/cyberleelawat/CVE-2025-20393.git
cd CVE-2025-20393

2️⃣ Run Scanner

Use domain

nuclei -u https://example.com -t /home/leelawat/Desktop/CVE-2025-20393/cve-2025-20393.yaml

Use subdomain list

nuclei -l subdomain.txt -t /home/leelawat/Desktop/CVE-2025-20393/cve-2025-20393.yaml

3️⃣ EXPOSURE CHECK

🛠️ Requirements

Active venv (Virtual Environment)

sudo apt update
sudo apt install python3-venv -y

python3 -m venv venv

source venv/bin/activate

• Python 3.8+
• Required Python libraries:
  root@kitploit:~

  pip install requests reportlab
  

4️⃣ 🚀 Usage

🔹 Basic Scan (Console Output Only)

python3 cve_2025_20393.py -u https://183.78.170.xxx/login

✅ Example Output

==============================
 CVE-2025-20393 EXPOSURE CHECK 
 Cisco Email Security Appliance
 Author: Virendra Kumar | Cyber Leelawat
==============================

[!!] EXPOSURE CONFIRMED ✅ (matches nuclei)
[+] URL      : https://183.78.170.xxx/login
[+] Status   : 200
[+] Version  : 11.0.4-004

Impact (Target-Specific):
- Internet-facing Cisco Email Security Appliance login panel exposed
- Exact AsyncOS version disclosed (11.0.4-004) enabling targeted attacks
- HTTPS service uses invalid/self-signed certificate (MITM risk)

5️⃣ 📄 Report Generation

🔹 Generate HTML & PDF Report (Current Directory)

python3 cve_2025_20393.py -u https://183.78.170.xxx/login -r

📂 Output

[+] Report Generated:

HTML: ./CVE-2025-20393-report.html
PDF : ./CVE-2025-20393-report.pdf

6️⃣🔹 Generate Report to Custom Path

python3 cve_2025_20393.py -u https://183.78.170.xxx/login -r /home/leelawat/Desktop/nasa/

📂 Output

[+] Report Generated:

HTML: /home/leelawat/Desktop/nasa/CVE-2025-20393-report.html
PDF : /home/leelawat/Desktop/nasa/CVE-2025-20393-report.pdf

⚠️ Legal Disclaimer

This repository is provided for educational and defensive security purposes only. The author is not responsible for misuse or illegal activities. Always obtain explicit permission before testing any system.

📚 References

1. Github (https://github.com/advisories/GHSA-mrgj-cg36-fgq8)
2. Nvd (https://nvd.nist.gov/vuln/detail/CVE-2025-20393)
3. CVE (https://www.cve.org/CVERecord?id=CVE-2025-20393)