bodyguard-of-bits 0.6.2

BOB — Bodyguard Of Bits: Linux hardening auditor with CIS benchmark mapping

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BOB — Bodyguard Of Bits

Linux hardening auditor for sysadmins who read the output.

BOB is a CLI security audit and hardening tool for Linux systems. It runs 43 checks across 7 score domains, maps findings to CIS benchmark sections when applicable, and shows not just what is wrong — but why it matters and how to fix it with concrete commands.

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Who it's for

• Sysadmins running periodic hardening reviews
• Power users who want more than a score and a list of flags
• Anyone tired of noisy, unactionable audit tools

BOB is not a scanner. It does not exploit, probe, or guess. It deterministically evaluates your configuration against CIS benchmarks and established best practices.

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Why BOB?

Lynis and OpenSCAP are solid, well-established tools — if you need broad compliance coverage or formal certification workflows, they're the right choice.

BOB serves a different purpose: practical hardening for sysadmins who need to act on findings, not file them. Every result comes with a plain-language explanation and a ready-to-run remediation command. The security score is context-aware — a machine directly exposed to the internet is held to a stricter standard than one behind NAT. Output is structured to be read in a terminal, not archived.

If you already run Lynis, BOB is not a replacement — it's a different lens, one that tells you what to do next.

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Install

Safety: BOB is audit-only. It executes only read-only commands (ss, dpkg-query, systemctl status, sysctl -n, ufw status, etc.) and never writes outside ~/.config/bob and its log directory. The optional --fix --apply mode prompts before each remediation; nothing else modifies system state. A typical audit completes in under 5 seconds.

pipx install bodyguard-of-bits
sudo bob

Bash completion:

sudo bob --install-completion

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Quick start

sudo bob                          # full audit, server profile
sudo bob --verbose                # add CIS refs and remediation commands per finding
sudo bob -d                       # French output
sudo bob --profile workstation    # workstation profile
sudo bob --check ssh,hardening    # run only selected domains
sudo bob --format json > out.json # machine output
bob --explain ssh.password_auth   # explain a finding (no sudo)

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Sample output

$ sudo bob

╔══════════════════════════════════════════════════════════════════════════════╗
║                            — Bodyguard Of Bits —                             ║
╠══════════════════════════════════════════════════════════════════════════════╣
║  BOB v0.6.2  │  Linux hardening auditor                                      ║
║  System        : Linux Mint 22.3                                             ║
║  Kernel        : 6.17.0-23-generic                                           ║
║  UFW           : v0.36.2                                                     ║
╚══════════════════════════════════════════════════════════════════════════════╝

━━━━━━━━━━━━━━━━━━━━━━━━━━━ SYSTEM HARDENING ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✔ [OK]    SYN flood protection active (tcp_syncookies=1)
✔ [OK]    ASLR fully enabled (randomize_va_space=2)
⚠ [WARN]  System sends ICMP redirects — exploitable for MITM on a non-router
   → sudo sysctl -w net.ipv4.conf.all.send_redirects=0
   [CIS:3.3.2]
   ? bob --explain hardening.send_redirects

╔══════════════════════════════════════════════════════════════════════════════╗
║  Security score   : 8/10  ↑ +1                                               ║
║  Risk level       : ✔ LOW                                                    ║
║  Firewall & Services  10/10  ██████████                                      ║
║  SSH                   7/10  ███████░░░                                      ║
║  System Hardening      4/10  ████░░░░░░                                      ║
╚══════════════════════════════════════════════════════════════════════════════╝

Every WARN/ALERT shows a CIS reference (when applicable), a copy-paste remediation command, and an --explain hint linking to the longer rationale.

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Security checks — 43 checks, 7 score domains

Domain	What it covers
Firewall	UFW rules, iptables/nftables (when UFW inactive), IPv6 consistency, port exposure
SSH	sshd_config hardening — PermitRootLogin, key strength, timeouts, forwarding
Kernel hardening	sysctl parameters, kernel modules, Secure Boot, firmware/microcode
Services	32 known services with risk classification; Docker firewall bypass detection
File permissions	SUID/SGID audit, sensitive files, sudoers
User accounts	Expired accounts, password policy, login.defs, PAM
System updates & detection	apt updates, auditd rules, Fail2ban, ClamAV, AppArmor/SELinux, AIDE/Tripwire integrity, rkhunter, SMART, firmware/microcode
Operations	Log rotation, auth.log analysis, NTP sync, TLS cert expiry, systemd timers, Samba, cron jobs
Network	Public IP context, network type detection (server/LAN/VPN), GeoIP optional
Docker	Daemon hardening, privileged containers, sensitive mounts

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CIS benchmark mapping

137 entries: 99 CIS Ubuntu 22.04 · 4 CIS Docker · 34 best-practice.

Each finding with a formal CIS code displays [CIS:X.Y.Z] inline in the summary box.
Full reference text is shown in --verbose mode.
--explain KEY returns the WHY, the HOW, and the CIS section — in plain English.

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--explain

bob --explain                     # interactive TUI — navigate findings with ↑↓, Enter to view
bob --explain ssh.password_auth   # direct lookup
bob --explain list                # list all explainable keys

No sudo required. Fully offline — no external calls or data collection.

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Audit profiles

Profile	Use case
server	Default — strict on SSH, firewall, services
desktop	Relaxed for desktop systems — SSH password auth tolerated, GUI apps not flagged, manual update mechanisms accepted (~11 overrides extending server)
workstation	Backward-compat alias to desktop
container	Extends desktop and skips host-level checks (kernel modules, kernel hardening, secure boot, auditd, suid_audit, docker_audit, file integrity, rootkit)

sudo bob --profile workstation

User-defined profiles: ~/.config/bob/profiles/

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Output formats

sudo bob                          # terminal (default)
sudo bob --format json            # JSON
sudo bob --format csv             # CSV
sudo bob --format markdown        # Markdown
sudo bob --html                   # standalone HTML report
sudo bob --output-dir /var/reports --format json

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Automation

Cron scheduling:

sudo bob --install-cron           # interactive wizard
sudo bob --manage-cron            # manage installed jobs

Jobs live in /etc/cron.d/bob-{name}. Email notification on exit code > 0.

Webhooks (generic JSON or Slack):

sudo bob --webhook https://hooks.slack.com/...

Score history and trends:

sudo bob --history                # sparkline of past scores

Diff mode:

sudo bob --diff                   # show only changes since last baseline

Score breakdown:

sudo bob --breakdown              # full score computation path (-B shorthand)
sudo bob -B

Watch mode:

sudo bob --watch=60               # rerun every 60 seconds

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Custom services

Drop a .json file into ~/.config/bob/services.d/ to extend the service registry:

{
  "id": "my_app",
  "name": "My App",
  "port": "9000/tcp",
  "risk": "medium"
}

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SUID whitelist

On Kali and other security-focused distributions, legitimate tools ship with the SUID bit set. Declare approved basenames or glob patterns in ~/.config/bob/config.conf to suppress them from the "unexpected SUID" warning:

# ~/.config/bob/config.conf
suid_whitelist = kismet_cap_*, my_enterprise_tool

Patterns are matched against the binary basename using fnmatch. Suppressed binaries are reported as INFO so the whitelist is always visible.

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Exit codes

Code	Meaning
0	Score ≥ 7 — no significant issues
1	Score 4–6 — warnings present
2	Score 1–3 — alerts present
3	Score 0 — critical issues
4	Score below --target N threshold (custom gate, e.g. bob --target 8 fails CI if score < 8)

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Requirements

• Python 3.10+
• Root (sudo)
• ss, systemctl — standard on most Linux systems

Optional: geoip2 for IP geolocation (pipx inject bodyguard-of-bits geoip2)

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Distribution support

Tier	Distros	Status
Tier 1 (daily-driven)	Linux Mint 22.x, Debian 13	Full feature set, validated on production hardware
Tier 2 (CI-validated)	Debian 12, Ubuntu 22.04/24.04/25.04, Kali Rolling, Fedora 41	Smoke + offline audit run on every PR; no locale sentinels, no Python tracebacks
Tier 3 (works but untested)	Other Debian/RHEL/SUSE/Arch-family Linux	Best-effort; checks degrade gracefully

On non-apt distributions (Fedora, RHEL, openSUSE, Arch), checks that rely on apt (e.g. pending security updates) emit INFO instead of WARN — BOB does not currently consume dnf/zypper/pacman metadata. CIS Ubuntu 22.04 references are still emitted when the underlying control (sysctl flags, SSH config, file permissions) is OS-agnostic.

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See also

• Full technical reference
• Changelog
• Developer guide
• Automation guide

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License

MIT — see LICENSE.

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Contributing

Issues and pull requests are welcome at github.com/Masbateno/bodyguard-of-bits. For substantial features, opening an issue first to discuss scope is appreciated.

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© 2026 Cédric Clauzel