Hardening sudo and PAM – Privilege Control in Linux

Why Privilege Escalation is a Risk

Most attackers don’t start with root. They pivot from low-privilege accounts. Misconfigured sudo rules and weak PAM policies are a direct highway to compromise.

Checklist for sudo Hardening

Least Privilege
```
%db_admins ALL=(ALL) /usr/bin/mysql
```
→ restrict to exact commands, not ALL.
No sudo without password
Audit /etc/sudoers for NOPASSWD: entries.
Logging sudo attempts
In journald, check:
```
journalctl _COMM=sudo
```

Checklist for PAM Hardening

Lockout Policy

auth required pam_tally2.so deny=5 unlock_time=600

Strong Password Policy
Use pam_pwquality:

minlen=12 ucredit=-1 lcredit=-1 dcredit=-1 ocredit=-1

MFA Integration
Add Google Authenticator or Duo via PAM modules.

Applied Example

Attack simulation: brute-force attempt triggers PAM lockout.
SOC alerted via journald → Wazuh integration.

Why Clients Care

Directly maps to CIS Control 6 (Access Control).
Prevents one compromised account from becoming a full breach.
Proves proactive measures to auditors.

Security gaps in Linux and cloud systems risk downtime, data compromise, lost business — and compliance failures.

With 20+ years’ experience and active UK Security Check (SC) clearance, I harden Linux and cloud platforms for government, corporate, and academic sectors — ensuring secure, compliant, and resilient infrastructure.

Contact for Contract Assignments