OpenTelemetry opentelemetry-exporter-otlp-proto-http 1.5.0 before 1.45.0 contains an improper certificate validation vulnerability that disables TLS verification when OTEL_EXPORTER_OTLP_CERTIFICATE variables are empty strings. Man-in-the-middle attackers can impersonate the collector to read or alter exported traces, metrics, and logs, including authentication headers from OTEL_EXPORTER_OTLP_HEADERS.