Hi Team, I am an independent security researcher and I have found a bug in your website The details of it are as follows:- Description: This report is about a misconfigured Dmarc/SPF record flag, which can be used for malicious purposes as it allows for fake mailing on behalf of respected organizations. About the Issue: As i have seen the DMARC record for gnu.org which is: DMARC Policy Not Enabled DMARC Not Found As u can see that you Weak SPF record, a valid record should be like:- DMARC Policy Enabled What's the issue: An SPF/DMARC record is a type of Domain Name Service (DNS) record that identifies which mail servers are permitted to send an email on behalf of your domain. The purpose of an SPF/DMARC record is to prevent spammers from sending messages on the behalf of your organization. Attack Scenario: An attacker will send phishing mail or anything malicious mail to the victim via mail: bug-gnuzilla@gnu.org even if the victim is aware of a phishing attack, he will check the origin email which came from your genuine mail id bug-gnuzilla@gnu.org so he will think that it is genuine mail and get trapped by the attacker. The attack can be done using any PHP mailer tool like this:- U can also check your Dmarc/ SPF record form: MXTOOLBOX Reference: https://support.google.com/a/answer/2466580?hl=en have a look at the GOOGLE article for a better understanding! [image: image.png] [image: image.png]