Skip to content

Clarify driver verification requirements for SRV records #1854

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Clarify driver verification requirements for SRV records #1854

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 9 additions & 0 deletions source/initial-dns-seedlist-discovery/initial-dns-seedlist-discovery.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -129,6 +129,12 @@ addition, SRV records with fewer than three `.` separated parts, the returned ho
domain level than the SRV record hostname. Drivers MUST raise an error and MUST NOT initiate a connection to any
returned hostname which does not fulfill these requirements.

> [!IMPORTANT]
> The driver verification requirement of host names returned through SRV records sharing the original SRV's `{domainname}`
> helps ensure that SRV-discovered hosts remain within the same parent domain as the URI. DNS records can be compromised,
> and without this check, an attacker could redirect clients to a malicious MongoDB instance under a different domain. \
> Requiring the same parent domain helps ensure that only hosts you control are trusted.

The driver MUST NOT attempt to connect to any hosts until the DNS query has returned its results.

If `srvMaxHosts` is zero or greater than or equal to the number of hosts in the DNS result, the driver MUST populate the
Expand Down Expand Up @@ -283,6 +289,9 @@ In the future we could consider using the priority and weight fields of the SRV

## ChangeLog

- 2025-10-30: Add an admonition clarifying the design decision from [SPEC-998](https://jira.mongodb.org/browse/SPEC-998)
that motivated the `{domainname}` validation requirement for host names within the SRV.

- 2024-09-24: Removed requirement for URI to have three '.' separated parts; these SRVs have stricter parent domain
matching requirements for security. Create terminology section. Remove usage of term `{TLD}`. The `{hostname}` now
refers to the entire hostname, not just the `{subdomain}`.
Expand Down
Loading