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PowerDNS / pdns

PowerDNS Authoritative, PowerDNS Recursor, dnsdist
https://www.powerdns.com/
GNU General Public License v2.0
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There is no validation of Null MX entry #13090

Open janwillemstegink opened 1 year ago

janwillemstegink commented 1 year ago

Program: Validation of record type MX Issue type: Bug report Short description More than one record in case of a Null MX record is not prevented. A user can fill the DNS in a way that is not according to clear RFC guidelines for Null MX.

Environment My test is at up-to-date provider TransIP, using PowerDNS. TransIP recently tested for me also in just PowerDNS: PowerDNS is not preventing such wrong setup

Steps to reproduce step 1: start for just a subdomain with www MX '0 .' and save

step 2: add a second record such as www MX '1 .' and save

Expected behaviour MX value '1 .' does not contain the valid priority 0 for Null MX. MX value '0 .' for Null MX requires no other record.

Actual behaviour No prevention. Wrong data can cause future problems.

Other information I did not find an earlier issue about this kind of validation. TransIP also suggests to build this validation in PowerDNS.

Habbie commented 1 year ago

Although I'm not sure I'd really call this a bug, we would accept a patch implementing this check.