Add 5s timeout to DNS auth lookup to prevent resource exhaustion #825
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The DNS auth endpoint was vulnerable to resource exhaustion if an attacker controlled a domain with a slow/non-responding authoritative DNS server. Without a timeout, handler goroutines would block on DNS resolution indefinitely, allowing an attacker to pile up goroutines until OOM. Production is protected by NGINX ingress's default 60s proxy timeout, but this adds defense-in-depth with a tighter 5s bound. Also fixes the vulnerability for local development which doesn't have NGINX in front.
rdimitrov
approved these changes
Dec 8, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The DNS auth endpoint was vulnerable to resource exhaustion if an attacker controlled a domain with a slow/non-responding authoritative DNS server. Without a timeout, handler goroutines would block on DNS resolution indefinitely, allowing an attacker to pile up goroutines until OOM.
Production is protected by NGINX ingress's default 60s proxy timeout, but this adds defense-in-depth with a tighter 5s bound.