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Security L5 SECURITY-1307 · 13 min

An OIDC mobile deep link works in test and fails in production because the registered redirect URI differs only by hostname case on the platform that treats it as exact

Everything looks identical to humans, yet the provider rejects the callback because the production platform enforces byte-level exact match.

SecurityPlatform ReliabilityLevel 5Pro13 min
Scenario

A mobile auth flow works in staging and later fails only in production after app-registration values were copied manually.

What to check first
  • Identify the primary failure signal in the Redirect URI Mismatch Hidden in Hostname Case scenario.
  • Separate visible symptoms from the underlying technical dependency.
  • Describe the safest recovery path and the follow-up prevention work.
Checking checklist
  1. Summarize the current impact and the last known change.
  2. Collect direct evidence from logs, runtime state, and configuration before changing anything.
  3. Separate immediate recovery from permanent prevention work.
Recovery and prevention

Diff registered and emitted redirect URIs byte-for-byte before rotating client secrets.

Questions worth viewing together
What should you verify first when An OIDC mobile deep link works in test and fails in production appears?

Community-field security problem inspired by mobile OIDC community threads where a redirect URI case mismatch broke the production callback. Humans treat hostnames case-insensitively; some auth registrations do not.

What usually causes An OIDC mobile deep link works in test and fails in production in production?

Teams often blame the SDK when the redirect mismatch is hidden in an apparently equivalent string.

What should you document after resolving An OIDC mobile deep link works in test and fails in production?

Manual auth client registration is vulnerable to trivial-looking exact-match drift.