Template / PR Information

• Added CVE-2021-20021 - SonicWall Email Security Broken Access Control (Critical)
• This template detects a critical vulnerability in SonicWall Email Security 10.0.9.x that allows unauthenticated attackers to create administrative accounts by sending crafted HTTP requests to the /createou endpoint without authentication.
• References:
  • https://nvd.nist.gov/vuln/detail/CVE-2021-20021
  • https://www.sonicwall.com/support/product-notification/security-notice-sonicwall-email-security-zero-day-vulnerabilities/210416112932360/
  • https://cloud.google.com/blog/topics/threat-intelligence/zero-day-exploits-in-sonicwall-email-security-lead-to-compromise
  • https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Template Validation

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Additional Details (leave it blank if not applicable)

Shodan Query: "SonicWall Email Security"

Template Testing Results:

[CVE-2021-20021] [http] [critical] http://localhost:8888/createou?data=test123
[CVE-2021-20021] [http] [critical] http://localhost:8888/createou [POST]
Scan completed in 5.228255ms. 5 matches found.

HTTP Response Snippet:

GET /createou?data=test123 HTTP/1.1
→ HTTP/1.0 400 Bad Request
→ Error in parsing request - SonicWall Email Security

POST /createou HTTP/1.1
→ HTTP/1.0 400 Bad Request  
→ Error in parsing request

Mock Server Used for Testing:

• Created Python mock server simulating vulnerable SonicWall Email Security
• Server responds with “Error in parsing request” for /createou endpoint
• Template successfully detects vulnerability signature
• Gist: https://gist.github.com/MAVRICK-1/49914b3391fbe17a9af372fef8cc45e7

Vulnerability Impact:

• CVSS Score: 9.8 (Critical)
• KEV Status: Active exploitation in the wild
• Allows creation of administrative accounts without authentication

Additional References:

• [Nuclei Template Creation Guideline](https://nuclei.projectdiscovery.io/templating-guide/)
• [Nuclei Template Matcher Guideline](https://github.com/projectdiscovery/nuclei-templates/wiki/Unique-Template-Matchers)
• [Nuclei Template Contribution Guideline](https://github.com/projectdiscovery/nuclei-templates/blob/master/CONTRIBUTING.md)
• [PD-Community Discord server](https://discord.gg/projectdiscovery)

Closes #12461

/claim #12461