DoS vulnerability for high cardinality metrics in opentelemetry-go-contrib

Vulnerability Description

opentelemetry-go-contrib is a collection of extensions for OpenTelemetry-Go. The v0.38.0 release of `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp` uses the `httpconv.ServerRequest` function to annotate metric measurements for the `http.server.request_content_length`, `http.server.response_content_length`, and `http.server.duration` instruments. The `ServerRequest` function sets the `http.target` attribute value to be the whole request URI (including the query string)[^1]. The metric instruments do not "forget" previous measurement attributes when `cumulative` temporality is used, this means the cardinality of the measurements allocated is directly correlated with the unique URIs handled. If the query string is constantly random, this will result in a constant increase in memory allocation that can be used in a denial-of-service attack. This issue has been addressed in version 0.39.0. Users are advised to upgrade. There are no known workarounds for this issue.

References

• https://github.com/open-telemetry/opentelemetry-go-contrib/security/advisories/GHSA-5r5m-65gx-7vrh
• https://github.com/open-telemetry/opentelemetry-go/blob/v1.12.0/semconv/internal/v2/http.go#L159