External Resources
Curated list of authoritative resources for Ubuntu Server security and administration.
Official Ubuntu Resources
Canonical/Ubuntu
| Resource | URL | Description |
| Ubuntu Server Guide | https://ubuntu.com/server/docs | Official documentation |
| Ubuntu Security | https://ubuntu.com/security | Security notices and tools |
| Ubuntu Pro | https://ubuntu.com/pro | Extended security and Livepatch |
| Ubuntu CVE Tracker | https://ubuntu.com/security/cves | Vulnerability database |
| Launchpad | https://launchpad.net/ubuntu | Bug tracking and packages |
| Ubuntu Wiki | https://wiki.ubuntu.com | Community documentation |
| Ubuntu Discourse | https://discourse.ubuntu.com | Community forums |
Security Notices
| Resource | URL | Description |
| USN | https://ubuntu.com/security/notices | Ubuntu Security Notices |
| Ubuntu Security Podcast | https://ubuntusecuritypodcast.org | Weekly security updates |
Security Standards and Benchmarks
CIS (Center for Internet Security)
| Resource | URL | Description |
| CIS Benchmarks | https://www.cisecurity.org/benchmark/ubuntu_linux | Ubuntu hardening guide |
| CIS Controls | https://www.cisecurity.org/controls | Security best practices |
| CIS-CAT | https://www.cisecurity.org/cybersecurity-tools/cis-cat-pro | Assessment tool |
NIST
| Resource | URL | Description |
| NIST CSF | https://www.nist.gov/cyberframework | Cybersecurity Framework |
| SP 800-123 | https://csrc.nist.gov/publications/detail/sp/800-123/final | Server Security Guide |
| SP 800-53 | https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/final | Security Controls |
| NVD | https://nvd.nist.gov | National Vulnerability Database |
DISA STIGs
| Resource | URL | Description |
| DISA STIGs | https://public.cyber.mil/stigs/ | Security Technical Implementation Guides |
| STIG Viewer | https://public.cyber.mil/stigs/srg-stig-tools/ | STIG viewing tool |
OWASP
| Resource | URL | Description |
| OWASP | https://owasp.org | Web security resources |
| OWASP Top 10 | https://owasp.org/Top10/ | Top web vulnerabilities |
| OWASP Cheat Sheets | https://cheatsheetseries.owasp.org | Security cheat sheets |
Linux Security Resources
General Linux Security
| Resource | URL | Description |
| Linux Security | https://linuxsecurity.com | News and tutorials |
| Kernel Security | https://www.kernel.org/doc/html/latest/admin-guide/security.html | Kernel documentation |
| systemd Security | https://systemd.io | systemd documentation |
Hardening Guides
| Resource | URL | Description |
| Lynis | https://cisofy.com/lynis/ | Security auditing tool |
| OpenSCAP | https://www.open-scap.org | SCAP security scanner |
| Tiger | https://www.nongnu.org/tiger/ | Security audit tool |
Networking and Firewall
| Resource | URL | Description |
| Netplan | https://netplan.io | Network configuration |
| nftables Wiki | https://wiki.nftables.org | Firewall documentation |
| UFW Documentation | https://wiki.ubuntu.com/UncomplicatedFirewall | UFW guide |
SSH Resources
| Resource | URL | Description |
| OpenSSH | https://www.openssh.com | Official OpenSSH site |
| SSH Audit | https://www.ssh-audit.com | SSH security scanner |
| Mozilla SSH Guidelines | https://infosec.mozilla.org/guidelines/openssh | SSH best practices |
Logging and Monitoring
| Resource | URL | Description |
| auditd | https://people.redhat.com/sgrubb/audit/ | Linux audit framework |
| rsyslog | https://www.rsyslog.com/doc/ | rsyslog documentation |
| journald | https://www.freedesktop.org/software/systemd/man/journald.conf.html | Journal configuration |
Package Management
| Tool | Documentation |
| APT | https://wiki.debian.org/Apt |
| dpkg | https://man7.org/linux/man-pages/man1/dpkg.1.html |
| Tool | Documentation |
| Fail2ban | https://www.fail2ban.org |
| AppArmor | https://gitlab.com/apparmor/apparmor/-/wikis/home |
| AIDE | https://aide.github.io |
| rkhunter | https://rkhunter.sourceforge.net |
Encryption
| Tool | Documentation |
| LUKS/cryptsetup | https://gitlab.com/cryptsetup/cryptsetup |
| GnuPG | https://gnupg.org/documentation/ |
Learning Resources
Online Courses
| Platform | Course | Description |
| Linux Foundation | Linux Security | Professional certification |
| Cybrary | Linux Security | Free security training |
| Pluralsight | Linux Administration | Comprehensive courses |
Books
| Title | Author | Topic |
| The Linux Command Line | William Shotts | Linux fundamentals |
| Linux Administration Handbook | Nemeth et al. | System administration |
| Linux Security Cookbook | Barrett et al. | Security recipes |
Practice Environments
| Resource | URL | Description |
| OverTheWire | https://overthewire.org/wargames/ | Security challenges |
| HackTheBox | https://www.hackthebox.com | Penetration testing labs |
| TryHackMe | https://tryhackme.com | Security training |
Forums and Q&A
| Resource | URL | Description |
| Ask Ubuntu | https://askubuntu.com | Ubuntu Q&A |
| Unix & Linux SE | https://unix.stackexchange.com | Linux Q&A |
| Server Fault | https://serverfault.com | Sysadmin Q&A |
Reddit
| Subreddit | Description |
| r/ubuntu | Ubuntu community |
| r/linuxadmin | Linux administration |
| r/netsec | Network security |
| r/sysadmin | System administration |
Mailing Lists
| List | URL | Description |
| ubuntu-security-announce | https://lists.ubuntu.com | Security announcements |
| oss-security | https://www.openwall.com/lists/oss-security/ | Open source security |
Vulnerability Resources
Databases
| Resource | URL | Description |
| CVE | https://cve.mitre.org | Common Vulnerabilities |
| NVD | https://nvd.nist.gov | National Vulnerability Database |
| Exploit-DB | https://www.exploit-db.com | Exploit database |
News and Alerts
| Resource | URL | Description |
| The Hacker News | https://thehackernews.com | Security news |
| Krebs on Security | https://krebsonsecurity.com | Security journalism |
| Schneier on Security | https://www.schneier.com | Security analysis |
Security Scanners
| Tool | URL | Description |
| Lynis | https://github.com/CISOfy/lynis | Security auditing |
| OpenSCAP | https://github.com/OpenSCAP/openscap | Compliance scanning |
| Nmap | https://nmap.org | Network scanner |
| Nikto | https://github.com/sullo/nikto | Web scanner |
Monitoring
| Tool | URL | Description |
| OSSEC | https://www.ossec.net | Host intrusion detection |
| Wazuh | https://wazuh.com | Security platform |
| Prometheus | https://prometheus.io | Monitoring system |
| Grafana | https://grafana.com | Visualization |
Keeping Current
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Quick Links
Most Used
| Resource | Direct Link |
| Ubuntu Security Notices | https://ubuntu.com/security/notices |
| CIS Ubuntu Benchmark | https://www.cisecurity.org/benchmark/ubuntu_linux |
| Ubuntu Server Docs | https://ubuntu.com/server/docs |
| Lynis Docs | https://cisofy.com/documentation/lynis/ |
| SSH Best Practices | https://infosec.mozilla.org/guidelines/openssh |
Emergency
| Situation | Resource |
| Ubuntu CVE | https://ubuntu.com/security/cves |
| Incident Response | Your organization's IR plan |
| Ubuntu Support | https://ubuntu.com/support |