Bucket Scanner

Declared vs real.
Object Storage security scanner — Yandex Cloud · AWS S3 · Azure · GCS
What you configured · what ACL allows · what the internet can actually reach.

FluxTap · Tracefuse · Timeforge · SignShield · Bucket Scanner

Discussions · Issues · #devsecops · #cspm · #object-storage · #yandex-cloud · #aws-s3

Why

Buckets drift. ACL says private, policy leaks public-read. Versioning is off, logging never enabled, a service account key outlived three rotations — and nobody noticed until exfil.

Bucket Scanner walks your Object Storage (Yandex Cloud by default, AWS S3 optional) and surfaces gaps between what you declare and what actually ships:

Metadata scan by default. Optional live probe proves reachability — without downloading object bodies.

╔══════════════════════════════════════════════════════════╗
║                      BUCKET SCANNER                      ║
║        declared vs real · object storage truth           ║
╚══════════════════════════════════════════════════════════╝

  score  42  ████████░░░░░░░░░░░░
  CRIT 1  HIGH 4  MED 7  LOW 2  INFO 3

  CHAIN  public-read + no-logging + stale-sa-key → silent exfil path

Part of the FounderB security stack: Tracefuse watches what you ship · FluxTap watches the wire · Bucket Scanner watches what you store.

Install

From PyPI (recommended):

pip install bucket-scanner
# pin: pip install bucket-scanner==1.3.0
bucket-scanner --help

From source (development):

git clone https://github.com/FounderB/BucketScanner.git
cd BucketScanner
python3 -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"
make hooks   # install local git author guard

See docs/PYPI.md for version pins and maintainer publishing.
Start here: docs/QUICKSTART.md · Golden demo: docs/GOLDEN_DEMO.md · Compliance: docs/COMPLIANCE.md

Requirements: Python 3.11+, Yandex Cloud credentials (default) or AWS credentials (--cloud aws). See docs/AWS.md.

AWS S3 (optional)

export AWS_REGION=us-east-1
bucket-scanner scan --cloud aws
bucket-scanner scan --cloud aws --fixture examples/demo-vulnerable/fixture-aws.toml
bucket-scanner doctor --cloud aws

Azure Blob (live + fixture)

pip install "bucket-scanner[azure]"
export AZURE_SUBSCRIPTION_ID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
bucket-scanner scan --cloud azure --folder-id "$AZURE_SUBSCRIPTION_ID"
bucket-scanner scan --cloud azure --fixture examples/demo-vulnerable/fixture-azure.toml
bucket-scanner explain azure/container-public-access

Live scan uses DefaultAzureCredential (env vars, managed identity, Azure CLI). See docs/AZURE.md.

Google Cloud Storage (live + fixture)

pip install "bucket-scanner[gcs]"
export GCP_PROJECT=my-gcp-project
bucket-scanner scan --cloud gcs --folder-id "$GCP_PROJECT"
bucket-scanner scan --cloud gcs --fixture examples/demo-vulnerable/fixture-gcs.toml

See docs/GCS.md.

Live Azure scan: pip install 'bucket-scanner[azure]' — see docs/AZURE.md.

60-second wow

All values under examples/demo-vulnerable/ are labeled FAKE / EXAMPLE.

# Offline demo — no cloud credentials required
bucket-scanner scan --fixture examples/demo-vulnerable/fixture.toml
bucket-scanner scan --fixture examples/demo-vulnerable/fixture.toml --json
bucket-scanner scan --fixture examples/demo-vulnerable/fixture.toml \
  --sarif /tmp/bucket-scanner.sarif --fail-on high

bucket-scanner scan --fixture examples/demo-vulnerable/fixture.toml \
  --repo examples/demo-vulnerable/repo \
  --tracefuse-report examples/demo-vulnerable/tracefuse-report.json \
  --prometheus /tmp/bucket-scanner.prom

# Prometheus + continuous monitoring
bucket-scanner serve --fixture examples/demo-vulnerable/fixture.toml --addr 127.0.0.1:9090

# Prove public exposure (anonymous probe, no object download)
bucket-scanner scan --folder-id b1gxxxxxxxxxx --probe

Expect findings across acl, policy, encryption, logging, versioning, lifecycle, iam, and chains. Exit 1 when policy fails; exit 2 on tool error.

Quick start

export YC_TOKEN=$(yc iam create-token)          # or YC_SERVICE_ACCOUNT_KEY_FILE
export YC_CLOUD_ID=b1g...
export YC_FOLDER_ID=b1g...

bucket-scanner scan --folder-id "$YC_FOLDER_ID"
bucket-scanner scan --folder-id "$YC_FOLDER_ID" --probe --fail-on high
bucket-scanner doctor                           # creds, scopes, API reachability
bucket-scanner explain acl/public-read          # remediation + why

Probe mode sends unauthenticated HTTP requests to bucket endpoints to verify real-world exposure. It never downloads object payloads — only checks reachability metadata.

Features

Also: health score, bucket-scanner init → .bucket-scanner.toml, doctor / explain, severity overrides, quiet mode for CI, SARIF 2.1.0 for GitHub Code Scanning, diff for Terraform drift.

Terraform drift

bucket-scanner diff examples/demo-vulnerable/terraform \
  --fixture examples/demo-vulnerable/fixture.toml

bucket-scanner scan --folder-id b1g... --terraform ./infra/storage/

Why not the console?

Use Bucket Scanner when you need one gate that answers “what does this folder actually risk?” — not just “is there a public ACL string somewhere?”

Who is this for?

5-minute path: docs/QUICKSTART.md · Rollout: docs/MIGRATION.md · OIDC CI: docs/OIDC.md

Comparison (honest)

CLI

bucket-scanner init [--preset yc-prod|aws-prod|...] [--force] [path]
bucket-scanner doctor                          # creds, folder access, API health
bucket-scanner explain <rule-id>               # remediation (e.g. acl/public-read)
bucket-scanner scan --folder-id ID             # human report
bucket-scanner scan --folder-id ID --json      # JSON to stdout
bucket-scanner scan --folder-id ID --sarif out.sarif --fail-on high
bucket-scanner scan --folder-id ID --baseline baselines/prod.json --fail-on new
bucket-scanner scan --folder-id ID --write-baseline baselines/prod.json
bucket-scanner scan --folder-id ID --probe     # + anonymous reachability checks
bucket-scanner inspect BUCKET                  # single-bucket deep report
bucket-scanner chain --sa-id ID                # blast radius from one SA
bucket-scanner diff PATH                       # Terraform vs live/fixture
bucket-scanner serve --addr 127.0.0.1:9090     # /metrics + /health
bucket-scanner list --folder-id ID             # inventory summary

Exit codes: 0 clean / below threshold · 1 policy fail · 2 tool error.

Default fail_on in config is high (overridable via --fail-on or .bucket-scanner.toml).

Configuration

bucket-scanner init writes .bucket-scanner.toml:

[scan]
folder_id = "b1gxxxxxxxxxx"
fail_on = "high"
probe = false

[scan.ignore_buckets]
names = ["public-assets-cdn"]

[[scan.severity_overrides]]
rule = "versioning/disabled"
severity = "medium"

See docs/CONFIGURATION.md for full reference.

Architecture

flowchart LR
  CLI["CLI<br/>scan · inspect · chain · doctor"] --> CFG[".bucket-scanner.toml"]
  CFG --> SCAN["scan::run_scan"]
  SCAN --> YC["YC Object Storage API<br/>metadata only"]
  SCAN --> PROBE["probe::anonymous<br/>optional HEAD/list"]
  YC --> DET["checks::*"]
  PROBE --> DET
  DET --> CHAIN["chains::compose"]
  CHAIN --> OUT["report<br/>human · json · sarif"]

Details: docs/ARCHITECTURE.md · docs/CHECKS.md

GitHub Actions

Minimal scan + SARIF upload. Full guide: docs/GITHUB_ACTION.md.

name: bucket-scanner
on:
  pull_request:
  push:
    branches: [main]
  schedule:
    - cron: "0 6 * * *"

permissions:
  contents: read
  security-events: write

jobs:
  scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.11"
      - run: pip install .
      - name: Scan YC folder
        env:
          YC_TOKEN: ${{ secrets.YC_TOKEN }}
          YC_FOLDER_ID: ${{ secrets.YC_FOLDER_ID }}
        run: |
          bucket-scanner scan --folder-id "$YC_FOLDER_ID" \
            --sarif bucket-scanner.sarif --fail-on high -q
      - name: Upload SARIF
        if: always()
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: bucket-scanner.sarif

Security promises

• Metadata by default — list buckets, ACLs, policies, settings; no bulk object download.
• Probe is opt-in — anonymous HTTP checks only when you pass --probe.
• Redaction — SA key fragments, tokens, and sensitive URLs redacted in all report formats.
• Offline fixtures — examples/demo-vulnerable/ uses clearly labeled FAKE/EXAMPLE values only.

See SECURITY.md and docs/AUDIT.md.

Roadmap

• Tracefuse hook — leaked YC_* in repo → cross-finding
• Prometheus exporter + Grafana dashboard
• Scheduled drift alerts (Telegram / webhook)
• AWS S3 backend (optional second cloud)
• Multi-region AWS inventory (per-bucket region resolution)
• Scheduled scan profiles in config
• CI/CD profile workflows (Action + scheduled matrix)
• Baseline/delta + suppressions for production CI gates
• Security hardening + audit docs (v0.11)
• PyPI package (pip install bucket-scanner)
• Azure Blob live scan (pip install bucket-scanner[azure])
• GCS backend (fixture-first)
• GCS live scan (pip install bucket-scanner[gcs])
• Golden demo walkthrough (docs/GOLDEN_DEMO.md)
• SARIF compliance tags (docs/COMPLIANCE.md)
• v1.0 stable — four-cloud live scan + PyPI + CI gates
• v1.1 — Terraform Azure/GCS drift, compliance export, Tracefuse polish
• v1.2 field deployment — prod profiles, baselines/, OIDC workflows (AWS/Azure/GCS), Grafana VM guide, multi-scope Azure/GCS

Community

GitHub topics: devsecops · cspm · object-storage · yandex-cloud · amazon-s3 · sarif · python

FounderB stack: Tracefuse (supply chain) · FluxTap (wire) · Bucket Scanner (object storage)

License

MIT © FounderB — LICENSE.

Contributing

CONTRIBUTING.md · CHANGELOG.md