otelhttp and otelbeego have DoS vulnerability for high cardinality metrics
### Impact The [v0.38.0](https://github.com/open-telemetry/opentelemetry-go-contrib/releases/tag/v1.13.0) release of [`go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp`](https://github.com/open-telemetry/opentelemetry-go-contrib/blob/463c2e7cd69d25f40b0a595b05394eeb26c68ae2/instrumentation/net/http/otelhttp/handler.go#L218) uses the [`httpconv.ServerRequest`](https://github.com/open-telemetry/opentelemetry-go/blob/v1.12.0/semconv/internal/v2/http.go#L159) 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. Pseudo-attack: ``` for infinite loop { r := generate_random_string() do_http_request("/some/path?random="+r) } ``` ### Patches - `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp` - v0.39.0 - `go.opentelemetry.io/contrib/instrumentation/github.com/astaxie/beego/otelbeego` - v0.39.0 [^1]: https://github.com/open-telemetry/opentelemetry-go/blob/6cb5718eaaed5c408c3bf4ad1aecee5c20ccdaa9/semconv/internal/v2/http.go#L202-L208
02 / AFFECTED SOFTWARE
Affected packages
72 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
### Impact The [v0.38.0](https://github.com/open-telemetry/opentelemetry-go-contrib/releases/tag/v1.13.0) release of [`go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp`](https://github.com/open-telemetry/opentelemetry-go-contrib/blob/463c2e7cd69d25f40b0a595b05394eeb26c68ae2/instrumentation/net/http/otelhttp/handler.go#L218) uses the [`httpconv.ServerRequest`](https://github.com/open-telemetry/opentelemetry-go/blob/v1.12.0/semconv/internal/v2/http.go#L159) 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. Pseudo-attack: ``` for infinite loop { r := generate_random_string() do_http_request("/some/path?random="+r) } ``` ### Patches - `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp` - v0.39.0 - `go.opentelemetry.io/contrib/instrumentation/github.com/astaxie/beego/otelbeego` - v0.39.0 [^1]: https://github.com/open-telemetry/opentelemetry-go/blob/6cb5718eaaed5c408c3bf4ad1aecee5c20ccdaa9/semconv/internal/v2/http.go#L202-L208
The otelhttp package of opentelemetry-go-contrib is vulnerable to a denial-of-service attack. The otelhttp package 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). The metric instruments do not "forget" previous measurement attributes when "cumulative" temporality is used, meaning that 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.
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.
05 / REFERENCES
Further evidence
- https://github.com/open-telemetry/opentelemetry-go-contrib
- 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
- https://nvd.nist.gov/vuln/detail/CVE-2023-25151
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/25xxx/CVE-2023-25151.json