On August 31, 2025, the Linux server administration community witnessed the end of an era as ConfigServer Security & Firewall (CSF) officially shut down after 20+ years of service. For hundreds of thousands of servers worldwide, CSF wasn’t just another utility – it was the cornerstone of their security infrastructure. The shutdown left many scrambling for alternatives, but with Centmin Mod, decisive action was made to ensure our users experience zero disruption.
Table of Contents
- The CSF Firewall Shutdown Announcement
- Centmin Mod’s Response: Continuity Through Self-Hosting
- CSF v15.00 GPLv3 Release: What Non-Centmin Mod Users Need to Know
- Community Sentiment and Alternative Solutions
- Looking Forward: The Future of Server Security
The CSF Firewall Shutdown Announcement
ConfigServer’s parent company, Way to the Web Ltd, announced the permanent closure of all operations with just one month’s notice. The official reason cited changing market dynamics that made the business “no longer profitable.” The shutdown affected all ConfigServer products including the free CSF/LFD suite and commercial tools like CXS and MSFE
The timing couldn’t have been more challenging. CSF’s architecture, built on iptables, faces obsolescence as RHEL 10 and future distributions move to nftables-only environments. This technological shift likely contributed to the decision to cease operations rather than undertake the massive re-engineering effort required for nftables compatibility.
However, there was a silver lining. Just before closure, ConfigServer released CSF v15.00 under the
GPLv3 and their other free scripts at https://github.com/waytotheweb/scripts, transforming the previously proprietary software into open-source. This crucial decision opened the door for community maintenance and continuation.
Once CSF Firewall is shutdown after August 31, 2025, if you have not switched to CSF v15.00, you may come across these CSF Firewall update errors:
/usr/sbin/csf -u Oops: Unable to download: Can’t connect to download.configserver.com:443 (Connection timed out)
or
/usr/sbin/csf -u Oops: Unable to download: Can’t connect to download2.configserver.com:443 (Connection timed out)
Centmin Mod’s Response: Continuity Through Self-Hosting
With Centmin Mod, to protect users from any disruption. Within days of the announcement, a comprehensive solution was implemented that ensures CSF continues to function seamlessly for all Centmin Mod installations that chose to update and apply this solution. See Centmin Mod forum discussions regarding this here.
Centmin Mod CSF Firewall Shutdown Handling
1. Self-Hosted Mirror Infrastructure
A permanent mirror at download.centminmod.com was established to serve as a reliable backup for existing Centmin Mod installations. This ensures that users can continue to use CSF v15.01 (Centmin Mod customized version based on the GPLv3 release). This ensures our users can continue installing and updating CSF without relying on the defunct ConfigServer servers.
2. Patched Auto-Update Mechanism
The CSF codebase to redirect all update checks and downloads to the Centmin Mod mirror infrastructure. Key changes include:
- Removed hardcoded references to
download.configserver.com - Updated
/etc/csf/downloadserversto point to our mirror - Modified
csget.plto use our version checking system - Preserved the familiar
csf -uauto-update functionality
3. Automated Migration for Existing Users
For existing Centmin Mod users, an update was made that can automatically switch their CSF installation to use the Centmin Mod mirror if they choose to do to. They can choose to do so by running cmupdate command to pull in latest Centmin Mod updates – one of which is updating an existing tools/csfcf.sh auto cronjob script with the ability to auto switch to Centmin Mod CSF Firewall mirrored version. This transparent migration means users don’t need to take any action – their CSF installation continues working exactly as before – beyond just running cmupdate command.
Implementation Details
For new Centmin Mod installations, they will automatically install the Centmin Mod CSF Firewall mirrored version.
For existing Centmin Mod installs, the transition process for Centmin Mod users is straightforward by just running cmupdate command:
cmupdate
Centmin Mod mirrored CSF v15.01 release maintains 100% compatibility with existing configurations while adding our infrastructure endpoints. This means all your existing csf.conf settings, allow/deny lists, and custom configurations remain intact.
CSF v15.00 GPLv3 Release: What Non-Centmin Mod Users Need to Know
For those not using Centmin Mod, the GPLv3 release of CSF v15.00 provides a path forward, though with more manual intervention required.
Key Changes in v15.00
The GPL release brought the following modifications that are also outlined at https://github.com/centminmod/configserver-scripts/blob/main/README-gpl-csf.md:
- License Headers: All 121 source files updated with GPLv3 boilerplate
- Auto-Update Disabled: Download server arrays emptied in
csget.pl - Attribution Updated: Copyright transferred to Jonathan Michaelson
- GitHub Availability: Source code available at
github.com/waytotheweb/scripts
Migration Steps for Non-Centmin Mod Users
If you’re running CSF outside of Centmin Mod, here’s what you need to do:
1. Backup Your Configuration
cp -R /etc/csf /etc/csf.backup cp /usr/local/csf/version.txt /usr/local/csf/version-backup.txt
2. Disable Auto-Updates
# Edit /etc/csf/csf.conf AUTO_UPDATES = "0" # Remove cron jobs rm -f /etc/cron.d/csf_update rm -f /etc/cron.daily/csget
3. Secure Download Servers
# Edit /etc/csf/downloadservers # Comment out or remove all entries to prevent connection attempts
4. Download CSF v15.00
cd /usr/src wget https://github.com/waytotheweb/scripts/raw/refs/heads/main/csf.tgz tar -xzf csf.tgz cd csf sh install.sh
Important Security Note: The ConfigServer domain remains registered until January 2027. To prevent potential security risks from domain hijacking, ensure your CSF installation cannot contact the old servers by clearing /etc/csf/downloadservers or pointing it to a trusted mirror.
Community Sentiment and Alternative Solutions
The CSF shutdown sparked extensive discussions across the hosting community, revealing both the depth of CSF’s integration and the variety of approaches being taken.
Control Panel Responses
DirectAdmin users face particular challenges as CSF was deeply integrated into their workflow. The
community is pursuing a few strategies: maintaining local self-hosted CSF copies for existing servers and transitioning to firewalld + fail2ban for new deployments. DirectAdmin’s Brute Force Monitor provides some protection but lacks LFD’s comprehensive log-scanning capabilities.
cPanel/WHM never officially bundled CSF, giving them more flexibility. Many cPanel users are evaluating Imunify360 ($12-45/month) as a commercial replacement, while budget-conscious administrators are combining cPHulk (built into cPanel) with firewalld and fail2ban for comparable protection.
Other panels like CWP and Hestia are actively developing firewalld-based replacements with GUI
integration, recognizing that most users need visual management tools.
Free Alternative Stack
The consensus for those seeking free alternatives centers on combining native Linux tools:
Firewalld + Fail2ban emerges as the most viable replacement:
- Firewalld handles packet filtering, port management, and zones
- Fail2ban provides log monitoring and dynamic IP blocking
- Combined, they cover ~90% of CSF+LFD functionality
The main trade-offs include:
- More complex initial setup (configuring fail2ban jails for each service)
- Loss of unified command interface (separate firewall-cmd and fail2ban-client)
- No integrated control panel UI without custom development
- Manual configuration of country blocking and advanced features
Commercial Alternatives
For those willing to pay for convenience:
- Imunify360 – Most comprehensive with AI-based threat detection, WAF, and malware scanning
- cPGuard – Expanding features to replace CSF functionality
- BitNinja – Server security suite with global IP reputation
Looking Forward: The Future of Server Security
The CSF shutdown represents a critical transition point for Linux server security. While the immediate crisis has been managed – existing installations continue working and the GPL release enables community maintenance – the long-term trajectory points toward fundamental changes.
Short-Term Outlook (Now – Q2 2026)
CSF will continue functioning on current systems (RHEL/AlmaLinux 8/9) with community support. Centmin Mod users have seamless continuity through the maintained CSF Firewall mirror version. Other users should secure their installations by disabling auto-updates and maintaining local copies.
Medium-Term Challenges (2026-2027)
The critical test comes with RHEL 10’s exclusive nftables support. Without significant development effort to add nftables compatibility to CSF, users will face forced migrations. The community’s ability to modernize CSF’s architecture will determine whether it remains viable or becomes a legacy tool.
Long-Term Evolution (2027+)
The industry will likely bifurcate between:
- Enterprise environments adopting commercial solutions with vendor support
- Technical teams mastering native Linux tools (firewalld/nftables + fail2ban)
- Potential emergence of a new open-source project designed for modern architectures
Centmin Mod Commitment
With Centmin Mod, for short to medium term the aim is to maintain CSF support as long as it remains technically viable. Also preparing alternative paths, including potential firewalld integration and enhanced security configurations, to ensure Centmin Mod users have robust options regardless of how the situation evolves.
The CSF shutdown reminds us that even foundational tools can disappear. By taking proactive measures – maintaining mirrors, preserving code, and developing alternatives – we can ensure that server security remains strong even as the tools change.
- For Centmin Mod users: The best path forward is to ensure you’re on latest Centmin
Mod 132.00stable or 140.00beta01 release and then runningcmupdatecommand to ensure you pull down latest updates which include the auto switching to Centmin Mod CSF Firewall mirror version. Your CSF installation continues working with the CSF Firewall mirror maintained version. See Centmin Mod forum discussions regarding this here. - For others: Secure your current CSF installation, evaluate alternatives, and consider joining
community efforts to maintain this critical infrastructure.