CVE-2023-45142 is a high-severity (CVSS 7.5) CWE-770 vulnerability in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp. A fix is available for go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp — see the affected versions and patch details below.
OpenTelemetry-Go Contrib has DoS vulnerability in otelhttp due to unbound cardinality metrics
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp🐹go.opentelemetry.io/contrib/instrumentation/github.com/emicklei/go-restful/otelrestful🐹go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin🐹go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux🐹go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho🐹go.opentelemetry.io/contrib/instrumentation/gopkg.in/macaron.v1/otelmacaron🐹go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptraceReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
This handler wrapper https://github.com/open-telemetry/opentelemetry-go-contrib/blob/5f7e6ad5a49b45df45f61a1deb29d7f1158032df/instrumentation/net/http/otelhttp/handler.go#L63-L65 out of the box adds labels
http.user_agenthttp.method
that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent to it.
Details
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.
PoC
Send many requests with long randomly generated HTTP methods or/and User agents (e.g. a million) and observe how memory consumption increases during it.
Impact
In order to be affected, the program has to configure a metrics pipeline, use otelhttp.NewHandler wrapper, and does not filter any unknown HTTP methods or User agents on the level of CDN, LB, previous middleware, etc.
Others
It is similar to already reported vulnerabilities
- https://github.com/open-telemetry/opentelemetry-go-contrib/security/advisories/GHSA-5r5m-65gx-7vrh (open-telemetry/opentelemetry-go-contrib)
- https://github.com/advisories/GHSA-cg3q-j54f-5p7p (prometheus/client_golang)
Workaround for affected versions
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.
The other possibility is to disable HTTP metrics instrumentation by passing otelhttp.WithMeterProvider option with noop.NewMeterProvider.
Solution provided by upgrading
In PR https://github.com/open-telemetry/opentelemetry-go-contrib/pull/4277, released with package version 0.44.0, 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.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp@v0.44.0 |
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/github.com/emicklei/go-restful/otelrestful | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/github.com/emicklei/go-restful/otelrestful@v0.44.0 |
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin@v0.44.0 |
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux@v0.44.0 |
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho@v0.44.0 |
| 🐹Go | go.opentelemetry.io/contrib/instrumentation/gopkg.in/macaron.v1/otelmacaron | all versions | 0.44.0go get go.opentelemetry.io/contrib/instrumentation/gopkg.in/macaron.v1/otelmacaron@v0.44.0 |
Affected Products
opentelemetryopentelemetryDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp to 0.44.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45142 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
While no authentication is required, there are a significant number of non-default factors which prevent widespread exploitation of this flaw. For a service to be affected, all of the following must be true: * The go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp package must be in use * Configured a…
As a workaround to stop being affected otelhttp.WithFilter() can be used. 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. The other possibility is to disable HTTP metrics instrumentation by passing otelhttp.WithMeterProvider option with noop.NewMeterProvider.Source: Red Hat security advisory for CVE-2023-45142 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Migration Toolkit for Virtualization 2.5 | migration-toolkit-virtualization/mtv-validation-rhel9:2.5.3-12 | RHBA-2023:7648 |
| OADP-1.3-RHEL-9 | oadp/oadp-mustgather-rhel9:1.3.0-138 | RHSA-2023:7555 |
| OADP-1.3-RHEL-9 | oadp/oadp-rhel9-operator:1.3.1-40 | RHSA-2024:1859 |
| Red Hat Advanced Cluster Management for Kubernetes 2.10 for RHEL 9 | rhacm2/acm-cluster-permission-rhel9:v2.10.5-5 | RHSA-2024:6236 |
| Red Hat Advanced Cluster Management for Kubernetes 2.9 for RHEL 8 | rhacm2/acm-governance-policy-addon-controller-rhel8:v2.9.3-9 | RHSA-2024:1328 |
| Red Hat Ceph Storage 5.3 | ceph-2:16.2.10-266.el8cp | RHSA-2024:4118 |
| Red Hat OpenShift Container Platform 4.12 | openshift4/ose-thanos-rhel8:v4.12.0-202402081808.p0.g2867a6b.assembly.stream.el8 | RHSA-2024:0833 |
| Red Hat OpenShift Container Platform 4.13 | openshift4/ose-thanos-rhel8:v4.13.0-202401292134.p0.g70fb57f.assembly.stream | RHSA-2024:0660 |
Frequently Asked Questions
Is CVE-2023-45142 in your dependencies?
Find it across Go, including transitive dependencies.