Public on 2023-10-12
Modified on 2024-02-06
OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. A handler wrapper out of the box adds labels `http.user_agent` and `http.method` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent to it. HTTP header User-Agent or HTTP method for requests can be easily set by an attacker to be random and long. The library internally uses `httpconv.ServerRequest` that records every value for HTTP `method` and `User-Agent`. In order to be affected, a program has to use the `otelhttp.NewHandler` wrapper and not filter any unknown HTTP methods or User agents on the level of CDN, LB, previous middleware, etc. Version 0.44.0 fixed this issue when the values collected for attribute `http.request.method` were changed to be restricted to a set of well-known values and other high cardinality attributes were removed. As a workaround to stop being affected, `otelhttp.WithFilter()` can be used, but it requires manual careful configuration to not log certain requests entirely. For convenience and safe usage of this library, it should by default mark with the label `unknown` non-standard HTTP methods and User agents to show that such requests were made but do not increase cardinality. In case someone wants to stay with the current behavior, library API should allow to enable it.
Important severity
CVSS v3 Base Score
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core amazon-cloudwatch-agent 2024-01-19 ALAS2-2024-2424 Fixed
Amazon Linux 2023 amazon-cloudwatch-agent 2024-01-19 ALAS2023-2024-498 Fixed
Amazon Linux 2 - Core cri-tools 2024-02-01 ALAS2-2024-2446 Fixed

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H