Observable Timing Discrepancy

Summary

OpenTelemetry, or OTel, is a vendor-neutral open source Observability framework for instrumenting, generating, collecting, and exporting telemetry data such as traces, metrics, and logs. The "bearertokenauth" extension's server authenticator performs a simple, non-constant time string comparison of the received & configured bearer tokens. This impacts anyone using the "bearertokenauth" server authenticator. Malicious clients with network access to the collector may perform a timing attack against a collector with this authenticator to guess the configured token, by iteratively sending tokens and comparing the response time. This would allow an attacker to introduce fabricated or bad data into the collector's telemetry pipeline. The observable timing vulnerability was fixed by using constant-time comparison. This issue affects github.com/open-telemetry/opentelemetry-collector-contrib/extension/bearertokenauthextension versions 0.80.0 through 0.106.1.