| Package | Affected versions | Patched versions |
|---|---|---|
| go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp | < 0.19.0 | 0.19.0 |
| go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp | < 1.43.0 | 1.43.0 |
| go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp | < 1.43.0 | 1.43.0 |
| opentelemetry | < 1.43.0 | 1.43.0 |
overview:
this report shows that the otlp HTTP exporters (traces/metrics/logs) read the full HTTP response body into an in-memory bytes.Buffer without a size cap.
this is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can mitm the exporter connection).
severity
HIGH
not claiming: this is a remote dos against every default deployment. claiming: if the exporter sends traces to an untrusted collector endpoint (or over a network segment where mitm is realistic), that endpoint can crash the process via a large response body.
callsite (pinned):
permalinks (pinned):
root cause:
each exporter client reads resp.Body using io.Copy(&respData, resp.Body) into a bytes.Buffer on both success and error paths, with no upper bound.
impact: a malicious collector can force large transient heap allocations during export (peak memory scales with attacker-chosen response size) and can potentially crash the instrumented process (oom).
affected component:
repro (local-only):
unzip poc.zip -d poc
cd poc
make canonical resp_bytes=33554432 chunk_delay_ms=0
expected output contains:
[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)
[PROOF_MARKER]: resp_bytes=33554432 peak_alloc_bytes=118050512
control (same env, patched target):
unzip poc.zip -d poc
cd poc
make control resp_bytes=33554432 chunk_delay_ms=0
expected control output contains:
[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)
[NC_MARKER]: resp_bytes=33554432 peak_alloc_bytes=512232
attachments: poc.zip (attached)
Fixed in: https://github.com/open-telemetry/opentelemetry-go/pull/8108
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