CVE-2024-45043

The OpenTelemetry Collector module AWS firehose receiver is for ingesting AWS Kinesis Data Firehose delivery stream messages and parsing the records received based on the configured record type. awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key. OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key. Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds). There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints. A fix was introduced in PR #34847 and released with v0.108.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

The OpenTelemetry Collector module AWS firehose receiver is for ingesting AWS Kinesis Data Firehose delivery stream messages and parsing the records received based on the configured record type. awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key. OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key. Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds). There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints. A fix was introduced in PR #34847 and released with v0.108.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Summary

OpenTelemetry Collector module awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key.

OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key.

Impact

Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds).

There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints.

Fix

A fix was introduced in https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/34847 and released with v0.108.0 (https://github.com/open-telemetry/opentelemetry-collector-releases/releases/tag/v0.108.0).

Details

<details> <summary>Details</summary>

PoC

When simulating Firehose requests against vulnerable versions of the Collector, we can see “UNAUTHORIZED METRICS” printed to the console via the debug exporter. (Note this script doesn’t run on some older still-vulnerable versions that do not have the “debug” exporter.)

#!/bin/bash

OTELCOL_VERSION=0.107.0
OTELCOL_BINARY="otelcol-contrib-${OTELCOL_VERSION}"
OTELCOL_PLATFORM="linux_amd64"
HOST_PORT=8081

cat > config.yaml << END
# https://opentelemetry.io/docs/collector/configuration/
exporters:
  debug:
    verbosity: normal
receivers:
  awsfirehose:
    endpoint : "127.0.0.1:${HOST_PORT}"
    record_type : "cwmetrics"
    access_key : "1234"
service:
  pipelines:
    metrics:
      receivers:
      - awsfirehose
      exporters:
      - debug
  telemetry:
    logs:
      encoding: "json"
      level: "debug"
END


if [ ! -x "${OTELCOL_BINARY}" ]; then
    curl --proto '=https' --tlsv1.2 -fOL https://github.com/open-telemetry/opentelemetry-collector-releases/releases/download/v${OTELCOL_VERSION}/otelcol-contrib_${OTELCOL_VERSION}_${OTELCOL_PLATFORM}.tar.gz
    tar -xvf otelcol-contrib_${OTELCOL_VERSION}_${OTELCOL_PLATFORM}.tar.gz otelcol-contrib
    mv otelcol-contrib ${OTELCOL_BINARY}
fi

"./${OTELCOL_BINARY}" --config=config.yaml &
OTELCOL_PID=$!

echo "Running OTel Collector with PID ${OTELCOL_PID}"

sleep 3

# Send metrics with correct access key
if ! curl --fail \
  -H "Content-Type: application/json"\
  -H "X-Amz-Firehose-Request-Id: requestId-valid"\
  -H "X-Amz-Firehose-Access-Key: 1234"\
  --data '{"requestId":"requestId-valid","timestamp":1723704887152,"records":[{"data":"eyJtZXRyaWNfc3RyZWFtX25hbWUiOiJ0ZXN0IiwiYWNjb3VudF9pZCI6IjEyMzQ1Njc4OSIsInJlZ2lvbiI6InVzLWVhc3QtMSIsIm5hbWVzcGFjZSI6IkFXUy9DbG91ZEZyb250IiwibWV0cmljX25hbWUiOiJSZXF1ZXN0cyIsImRpbWVuc2lvbnMiOnsiRGlzdHJpYnV0aW9uSWQiOiJBQkNEIiwiUmVnaW9uIjoiR2xvYmFsIn0sInRpbWVzdGFtcCI6MTcyMzcwNDU0MDAwMCwidmFsdWUiOnsibWF4IjoxLjAsIm1pbiI6MS4wLCJzdW0iOjkuMCwiY291bnQiOjkuMH0sInVuaXQiOiJOb25lIn0="}]}'\
  http://127.0.0.1:${HOST_PORT}
then
    echo "Unexpected – Request with valid access key did not…

The OpenTelemetry Collector module AWS firehose receiver is for ingesting AWS Kinesis Data Firehose delivery stream messages and parsing the records received based on the configured record type. awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key. OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key. Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds). There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints. A fix was introduced in PR #34847 and released with v0.108.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

The OpenTelemetry Collector module AWS firehose receiver is for ingesting AWS Kinesis Data Firehose delivery stream messages and parsing the records received based on the configured record type. awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key. OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key. Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds). There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints. A fix was introduced in PR #34847 and released with v0.108.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Summary

OpenTelemetry Collector module awsfirehosereceiver allows unauthenticated remote requests, even when configured to require a key.

OpenTelemetry Collector can be configured to receive CloudWatch metrics via an AWS Firehose Stream. Firehose sets the header X-Amz-Firehose-Access-Key with an arbitrary configured string. The OpenTelemetry Collector awsfirehosereceiver can optionally be configured to require this key on incoming requests. However, when this is configured it still accepts incoming requests with no key.

Impact

Only OpenTelemetry Collector users configured with the “alpha” awsfirehosereceiver module are affected. This module was added in version v0.49.0 of the “Contrib” distribution (or may be included in custom builds).

There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data. It’s likely these endpoints will be exposed to the public internet, as Firehose does not support private HTTP endpoints.

Fix

A fix was introduced in https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/34847 and released with v0.108.0 (https://github.com/open-telemetry/opentelemetry-collector-releases/releases/tag/v0.108.0).

Details

<details> <summary>Details</summary>

PoC

When simulating Firehose requests against vulnerable versions of the Collector, we can see “UNAUTHORIZED METRICS” printed to the console via the debug exporter. (Note this script doesn’t run on some older still-vulnerable versions that do not have the “debug” exporter.)

#!/bin/bash

OTELCOL_VERSION=0.107.0
OTELCOL_BINARY="otelcol-contrib-${OTELCOL_VERSION}"
OTELCOL_PLATFORM="linux_amd64"
HOST_PORT=8081

cat > config.yaml << END
# https://opentelemetry.io/docs/collector/configuration/
exporters:
  debug:
    verbosity: normal
receivers:
  awsfirehose:
    endpoint : "127.0.0.1:${HOST_PORT}"
    record_type : "cwmetrics"
    access_key : "1234"
service:
  pipelines:
    metrics:
      receivers:
      - awsfirehose
      exporters:
      - debug
  telemetry:
    logs:
      encoding: "json"
      level: "debug"
END


if [ ! -x "${OTELCOL_BINARY}" ]; then
    curl --proto '=https' --tlsv1.2 -fOL https://github.com/open-telemetry/opentelemetry-collector-releases/releases/download/v${OTELCOL_VERSION}/otelcol-contrib_${OTELCOL_VERSION}_${OTELCOL_PLATFORM}.tar.gz
    tar -xvf otelcol-contrib_${OTELCOL_VERSION}_${OTELCOL_PLATFORM}.tar.gz otelcol-contrib
    mv otelcol-contrib ${OTELCOL_BINARY}
fi

"./${OTELCOL_BINARY}" --config=config.yaml &
OTELCOL_PID=$!

echo "Running OTel Collector with PID ${OTELCOL_PID}"

sleep 3

# Send metrics with correct access key
if ! curl --fail \
  -H "Content-Type: application/json"\
  -H "X-Amz-Firehose-Request-Id: requestId-valid"\
  -H "X-Amz-Firehose-Access-Key: 1234"\
  --data '{"requestId":"requestId-valid","timestamp":1723704887152,"records":[{"data":"eyJtZXRyaWNfc3RyZWFtX25hbWUiOiJ0ZXN0IiwiYWNjb3VudF9pZCI6IjEyMzQ1Njc4OSIsInJlZ2lvbiI6InVzLWVhc3QtMSIsIm5hbWVzcGFjZSI6IkFXUy9DbG91ZEZyb250IiwibWV0cmljX25hbWUiOiJSZXF1ZXN0cyIsImRpbWVuc2lvbnMiOnsiRGlzdHJpYnV0aW9uSWQiOiJBQkNEIiwiUmVnaW9uIjoiR2xvYmFsIn0sInRpbWVzdGFtcCI6MTcyMzcwNDU0MDAwMCwidmFsdWUiOnsibWF4IjoxLjAsIm1pbiI6MS4wLCJzdW0iOjkuMCwiY291bnQiOjkuMH0sInVuaXQiOiJOb25lIn0="}]}'\
  http://127.0.0.1:${HOST_PORT}
then
    echo "Unexpected – Request with valid access key did not…

OpenTelemetry Collector module AWS Firehose Receiver Authentication Bypass Vulnerability in github.com/open-telemetry/opentelemetry-collector-contrib/receiver/awsfirehosereceiver