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):
- exporters/otlp/otlptrace/otlptracehttp/client.go:199
- exporters/otlp/otlptrace/otlptracehttp/client.go:230
- exporters/otlp/otlpmetric/otlpmetrichttp/client.go:170
- exporters/otlp/otlpmetric/otlpmetrichttp/client.go:201
- exporters/otlp/otlplog/otlploghttp/client.go:190
- exporters/otlp/otlplog/otlploghttp/client.go:221
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:
- go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp
- go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp
- go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp
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)
PR_DESCRIPTION.md
attack_scenario.md
poc.zip
Fixed in: open-telemetry/opentelemetry-go#8108
References
overview:
this report shows that the otlp HTTP exporters (traces/metrics/logs) read the full HTTP response body into an in-memory
bytes.Bufferwithout 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.Bodyusingio.Copy(&respData, resp.Body)into abytes.Bufferon 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=0expected output contains:
control (same env, patched target):
unzip poc.zip -d poc cd poc make control resp_bytes=33554432 chunk_delay_ms=0expected control output contains:
attachments: poc.zip (attached)
PR_DESCRIPTION.md
attack_scenario.md
poc.zip
Fixed in: open-telemetry/opentelemetry-go#8108
References