October 31, 2026
One DNS Lookup. Two Email Security Gaps. A Responsible Disclosure Story.
How passive DNS reconnaissance uncovered email authentication weaknesses in a Sainik School domain.
By Praveen Rathod(Radhe_karn)
1 min read
By Praveen Rathod | Independent Security Researcher
🔍 The Discovery
Sometimes, interesting security findings don't require advanced exploitation tools. A simple DNS investigation can reveal more than you might expect.
During a passive DNS security review of ssbj.in, I decided to examine its publicly available email authentication records.
What I discovered?
Two potential email security configuration weaknesses.
What Did I Find?
1. Missing DMARC Record
A DNS lookup for _dmarc.ssbj.in returned NXDOMAIN, indicating that no DMARC record was published at the time of testing.
2. SPF SoftFail Configuration
The domain had an SPF record ending in ~all (SoftFail), rather than the stricter -all (HardFail) mechanism.
These configurations highlighted opportunities to strengthen the domain's email authentication.
How Did I Discover It?
I used basic DNS reconnaissance with the dig utility.
The investigation involved:
- Checking DMARC TXT records.
- Inspecting the domain's SPF configuration.
- Reviewing DNS responses.
- Identifying potential email authentication weaknesses.
No exploitation. No unauthorized access. Just passive DNS analysis.
🎯 Why Should Organizations Care?
Email is one of the most commonly used communication channels for institutions.
Weak email authentication configurations can increase exposure to domain impersonation and phishing, depending on other security controls.
For educational institutions, protecting official email communications is especially important.
🛡️ My Recommendations
- Deploy a properly configured DMARC policy.
- Review and validate SPF-authorized senders.
- Enable DKIM authentication.
- Monitor DMARC reports regularly.
Responsible Disclosure
I documented the findings and privately reported them to the relevant institution to help improve its email security posture.
My assessment remained strictly within passive DNS verification.
Final Thoughts
You don't always need to break into a system to identify a security weakness. Sometimes, all you need is curiosity, a terminal, and the right questions.
This small investigation reminded me that cybersecurity begins with observation.
Keep learning. Keep researching. Stay ethical.
Praveen Rathod (Radheya_karn) Independent Security Researcher
#CyberSecurity #EthicalHacking #DNSReconnaissance #EmailSecurity #DMARC #SPF #ResponsibleDisclosure #BugHunting #SecurityResearch