bug#49260: closed (Vulnerability Report [Misconfigured DMARC Record Flag])

[GNU bug Tracking System]

Your message dated Sat, 17 Jul 2021 02:11:51 -0400
with message-id <877dhpsc3h.fsf@netris.org>
and subject line Re: bug#49260: Vulnerability Report [Misconfigured DMARC 
Record Flag]
has caused the debbugs.gnu.org bug report #49260,
regarding Vulnerability Report [Misconfigured DMARC Record Flag]
to be marked as done.

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49260: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=49260
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--- Begin Message --- Subject: Vulnerability Report [Misconfigured DMARC Record Flag] Date: Mon, 28 Jun 2021 22:28:23 +0500

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:-

<?php
$to = "VICTIM@example.com";
$subject = "Password Change";
$txt = "Change your password by visiting here - [VIRUS LINK HERE]l";
$headers = "From: 

bug-gnuzilla@gnu.org

";mail($to,$subject,$txt,$headers);
?>

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!

--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#49260: Vulnerability Report [Misconfigured DMARC Record Flag]
>
>
>
>
> Date: 
>
> Sat, 17 Jul 2021 02:11:51 -0400
>
>
>
>
> Ian Kelling <iank@fsf.org> writes:
>
> > We have a dmarc policy. It is called "none". we are not doing anything
> > insecure or unusual, for example it is the same one that google uses:
> >
> > $ host -t txt _dmarc.gmail.com
> > _dmarc.gmail.com descriptive text "v=DMARC1; p=none; sp=quarantine; 
> > rua=mailto:mailauth-reports@google.com";
> > $ host -t txt _dmarc.gnu.org
> > _dmarc.gnu.org descriptive text "v=DMARC1; p=none; 
> > rua=mailto:dmarc-rua@fsf.org";
> >
> > Someone can close this bug.
>
> Agreed.  I'm closing this bug now.  Thanks, Ian.
>
>       Mark
>
> -- 
> Disinformation flourishes because many people care deeply about injustice
> but very few check the facts.  Ask me about <https://stallmansupport.org>.
>
>
> --- End Message ---