title: DoS vulnerability for high cardinality metrics in opentelemetry-go-contrib
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.
problem types: CWE-400: Uncontrolled Resource Consumption
affected:
{
vendor: open-telemetry
product: opentelemetry-go-contrib
versions:
version: >= 0.38.0, < 0.39.0, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]