Linux Server Hardening & Security Pack
We fortify production Linux servers (Ubuntu, Debian, AlmaLinux, RHEL) against automated botnets, ransomware, dictionary attacks, and kernel exploits. A complete, kernel-native security overhaul delivered as self-managed scripts or turnkey engineering service.
Everything Included in the Hardening Solution
Every component is engineered natively in Linux subsystems without third-party agent bloat:
Automated Hardening Script Suite (.sh)
Battle-tested, idempotent Bash scripts tailored for Ubuntu, Debian, AlmaLinux, and RHEL with dry-run safety mechanisms.
Stateful NFTables / UFW Firewall Filter
Default-DROP inbound perimeter with connection tracking, RFC 3704 anti-spoofing, and granular port rate-limiting.
Optimized Kernel Sysctl Profile
Full ASLR Level 2 memory randomization, TCP SYN flood defense, kernel pointer masking, and unprivileged eBPF lockdown.
Cryptographic SSH & PAM Lockdown
Mandatory Ed25519 elliptic-curve keys, root direct login disabled, custom port binding, and PAM faillock brute-force defense.
Filesystem Mount & SUID Fortification
World-writable directories (/tmp, /dev/shm) mounted with noexec/nosuid/nodev, and privileged SUID binary sanitization.
Lynis CIS Benchmark Audit Report (PDF)
Pre- and post-hardening vulnerability assessment verifying a 95+ CIS benchmark compliance score for management and compliance.
Four Integrated Layers of Fortification
Security is not just a firewall. We harden your server across every layer of the operating system stack:
Kernel & Memory Fortification
Locks down the Linux kernel attack surface by preventing memory corruption exploits, hiding kernel pointers, disabling unprivileged eBPF execution, and neutralizing TCP SYN floods.
- ✓
kernel.randomize_va_space = 2 (Full Address Space Layout Randomization) - ✓
kernel.kptr_restrict = 2 (Complete kernel symbol pointer hiding) - ✓
kernel.unprivileged_bpf_disabled = 1 (Block unprivileged eBPF syscalls) - ✓
fs.suid_dumpable = 0 (Disable SUID core dumps to protect credentials)
Stateful Network & Firewall Filter
Replaces permissive default routing with a strict default-drop stateful firewall, connection tracking, anti-spoofing reverse path filtering, and granular rate-limiting.
- ✓
Default DROP policy for all unsolicited inbound IPv4 and IPv6 traffic - ✓
NFTables rate limiting for SSH (5 new conns/min) and Web daemons - ✓
net.ipv4.conf.all.rp_filter = 1 (Strict RFC 3704 anti-spoofing validation) - ✓
Automated TCP SYN Cookie activation under network flood stress
SSH & Identity Access Lockdown
Completely eliminates automated password dictionary attacks by forcing Ed25519 elliptic curve keys, disabling direct root logins, and applying PAM failed-attempt locks.
- ✓
PasswordAuthentication no & PermitRootLogin no enforced across all daemons - ✓
Strict KexAlgorithms curve25519-sha256 and ChaCha20-Poly1305 ciphers - ✓
Custom obfuscated administrative port binding to eliminate bot scans - ✓
PAM faillock / pam_tally2 integration to freeze abusive IP addresses
Filesystem & Mount Hardening
Restricts attackers from executing uploaded malicious payload scripts in world-writable temporary directories and audits all privileged SUID/SGID binaries.
- ✓
Mount /tmp, /var/tmp, and /dev/shm with nodev, nosuid, noexec flags - ✓
SUID & SGID binary vulnerability audit with removal of unnecessary bits - ✓
fs.protected_hardlinks = 1 & fs.protected_symlinks = 1 kernel enforcement - ✓
Strict 0700 permissions on all administrative home directories and keys
Structured & Safe Deployment Process
How our senior security engineers execute your server fortification from start to finish:
Discovery & Configuration Backup
We inspect your active OS distribution, daemon ports, and CMS stack, then create an isolated atomic recovery snapshot in /var/backups/ before making any modifications.
Non-Disruptive Hardening Rollout
Our engineers deploy the kernel sysctl profile, NFTables rules, and SSH policies in staged dry-runs. Active SSH sessions, live HTTP traffic, and database queries remain uninterrupted.
Lynis CIS Benchmark Verification
We run deep post-deployment diagnostic scans to verify that all attack vectors are sealed and the system achieves a verified 95+ CIS benchmark compliance score.
Access Revocation & Handover
All temporary Ed25519 public keys used for the session are cleanly revoked, sudo caches are flushed, and you receive the executive PDF report and technical warranty.
Enforced Kernel & Daemon Parameters
Key parameters automatically configured, validated, and verified by our hardening suite:
| Security Parameter | Hardened Value | Defensive Impact |
|---|---|---|
kernel.randomize_va_space | 2 | Enforces maximum ASLR randomization against memory exploits |
net.ipv4.tcp_syncookies | 1 | Protects TCP backlog against SYN flood DoS attacks |
net.ipv4.conf.all.rp_filter | 1 | Validates source address to prevent IP address spoofing |
net.ipv4.conf.all.accept_redirects | 0 | Prevents malicious ICMP routing table alterations |
kernel.dmesg_restrict | 1 | Prevents non-root users from reading kernel log buffer |
kernel.kptr_restrict | 2 | Masks /proc/kallsyms pointers from privilege escalation exploits |
fs.suid_dumpable | 0 | Disables memory core dumping from setuid binaries |
PermitRootLogin | no | Blocks direct root access; requires non-root authenticated user |
PasswordAuthentication | no | Rejects all password attempts; requires cryptographic SSH key |
MaxAuthTries | 3 | Disconnects and bans clients exceeding 3 failed attempts |
NFTables Input Policy | DROP | Drops all unsolicited ports except strictly authorized services |
Fail2ban Jail Mode | Aggressive | Issues 24h+ bans on repeated auth failures & port probing |
Choose Your Hardening Tier
Transparent one-time fees. No recurring subscriptions or hidden licensing costs.
Ready-Made Script Pack
Full suite of documented Bash hardening scripts, sysctl security profile, NFTables rules, and step-by-step PDF manual.
- ✓Complete Bash hardening script suite (.sh)
- ✓Pre-configured sysctl.conf & nftables.conf
- ✓Fail2ban multi-jail configuration files
- ✓Step-by-step PDF installation & verification manual
- ✓14-day script update support
Turnkey Installation
Our security engineers deploy, configure, and verify the hardening pack directly on your server without service disruption.
- ✓All scripts & configuration templates included
- ✓Direct turnkey deployment by Khodshima engineers
- ✓Dry-run pre-flight validation and config backup
- ✓Active session protection & continuous uptime guarantee
- ✓Web stack / Database basic isolation
- ✓30-day post-installation engineering warranty
Full Audit + Hardening
Exhaustive pre-hardening vulnerability scan + Turnkey Hardening + Post-hardening CIS compliance audit and executive PDF report.
- ✓Complete turnkey hardening across all 4 defense layers
- ✓Pre- and post-hardening Lynis CIS Benchmark audit
- ✓Full vulnerability diagnostic & executive PDF report
- ✓Web stack, PHP-FPM sandbox, and DB firewalling
- ✓Scheduled intrusion detection (rkhunter / ClamAV)
- ✓60-day engineering warranty & re-scan guarantee