SMTP Pentest Guide

Responsible Disclosure Guidelines

What is Responsible Disclosure?

Responsible disclosure is a vulnerability disclosure model in which a vulnerability or security issue is disclosed to the public only after the responsible parties have been allowed sufficient time to patch or remedy the vulnerability.

Guidelines for Responsible Disclosure

1. Verify the Vulnerability

Before reporting, ensure that you have thoroughly verified the vulnerability and can reproduce it consistently. Document the steps to reproduce the issue clearly.

2. Report Promptly

Once you have verified a vulnerability, report it to the organization as soon as possible. Many organizations have dedicated security contact emails or vulnerability disclosure programs.

3. Provide Detailed Information

Include the following in your report:

  • A clear description of the vulnerability
  • Steps to reproduce the issue
  • Potential impact of the vulnerability
  • Any suggestions for mitigation or fixes
  • Screenshots or videos demonstrating the issue (if applicable)

4. Respect Privacy and Data

During your testing:

  • Do not access, modify, or delete data that does not belong to you
  • Do not exfiltrate sensitive data, even to demonstrate the vulnerability
  • Minimize the testing required to prove the vulnerability

5. Allow Time for Remediation

Give the organization reasonable time to investigate and address the reported vulnerability before disclosing it publicly. The standard practice is to wait at least 90 days, but this can vary depending on the severity and complexity of the issue.

6. Coordinate Public Disclosure

If you plan to publish your findings, coordinate with the affected organization to ensure they have had adequate time to address the issue. This helps protect users while still allowing for transparency.

SMTP-Specific Considerations

When testing SMTP servers specifically:

  • Never send unauthorized emails through vulnerable systems
  • Do not attempt to access or read others' emails
  • Avoid causing denial of service to mail systems
  • Be cautious with automated scanning tools that might trigger alerts

Legal Protections

Be aware that not all organizations have vulnerability disclosure policies, and security testing without explicit permission may violate laws in some jurisdictions. Always:

  • Check if the organization has a published security policy or bug bounty program
  • Get written permission before testing if no policy exists
  • Understand the legal framework in your jurisdiction regarding security research

Sample Disclosure Template

Subject: Security Vulnerability Report - [Brief Description]

Dear [Organization] Security Team,

I am writing to report a security vulnerability I discovered in your SMTP server at [hostname/IP].

Vulnerability Details:
- Type: [e.g., SMTP Open Relay, Authentication Bypass]
- Severity: [Critical/High/Medium/Low]
- Affected Component: [e.g., Postfix 2.10.1 on mail.example.com]

Steps to Reproduce:
1. [Clear step-by-step instructions]
2. [...]
3. [...]

Potential Impact:
[Description of what an attacker could potentially do by exploiting this vulnerability]

Suggested Mitigation:
[If you have suggestions for fixing the issue]

I have followed responsible disclosure practices and have not disclosed this vulnerability to anyone else. I will maintain confidentiality until you have had reasonable time to address the issue.

Please let me know if you need any additional information.

Regards,
[Your Name]
[Contact Information]