Despite the value of dmesg_restrict, the kernel log will still be displayed in the console during boot. Malware that is able to record the screen during boot may be able to abuse this to gain higher privileges. This must be used in combination with certain boot parameters described below to be fully effective. Next, you need to disable the booting from external media devices (USB/CD/DVD). If you omit to change this setting, anyone can use a USB stick that contains a bootable OS and can access your OS data. Therefore, in addition to hardening your systems, you need additional defenses.
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Use a secure password that follows the same policy that the rest of your operating-system-level passwords use. Pick a password that is different than any of the other passwords that you use for your system. Another potential networking pitfall is the use of centralized computing. A common cost-cutting measure for many businesses is to consolidate all services to a single powerful machine.
Linux Server Hardening and Security Best Practices
The header is stored in a detached location, which also serves as an additional layer of security. This mode stores individual checksums of the sectors in the re-encryption area, which the recovery process can detect for the sectors that were re-encrypted by LUKS2. Red Hat Enterprise Linux provides several tools for checking and preserving the integrity of files and directories on your system.
Some software such as Docker, Podman, and LXC require unprivileged user namespaces to function. If you use these tools you should not disable kernel.unprivileged_userns_clone. We strongly recommend that you learn what these options do before applying them. There are also some methods of kernel attack surface reduction and access restrictions to sysfs that can further improve security.
6.3. Threats to workstation and home PC security
You can use an analogous procedure when using a TPM 2.0 policy instead of a Tang server. Hashes in PCRs can be rewritten, and you no longer can unlock your linux hardening and security lessons encrypted volume. For this reason, add a strong passphrase that enable you to unlock the encrypted volume manually even when a value in a PCR changes.
- Follow the steps to prepare and apply an Ansible playbook containing your Tang server settings.
- To use encrypted transport through TLS, configure both the server and the client.
- Apply rules in iptables to filters incoming, outgoing and forwarding packets.
- You can also create and manage your SCAP security policies entirely within the compliance service UI.
- This checklist is created based on years of expertise in the field of Linux security.
- You can modify (tailor) a profile to customize certain rules, for example, password length.
This guide also provides you with practical step-by-step instructions for building your own hardened systems and services. One of the main goals is to create a single document covering internal and external threats. In the Linux kernel, "root privileges" are split up into various different capabilities. This is helpful in applying the principle of least privilege — instead of giving a process total root privileges, you can grant them only a specific subset instead. For example, if a program simply needs to set your system time, then it only needs CAP_SYS_TIME rather than total root.
Linux Security Expert
So, it’s not a good idea to have this option enabled at least on production servers, if someone by mistakenly does this. This is very useful if you want to disallow users to use same old passwords. Cron has it’s own built in feature, where it allows to specify who may, and who may not want to run jobs. This is controlled by the use of files called /etc/cron.allow and /etc/cron.deny.
- With the logging System Role, you can combine the inputs and outputs to fit your scenario.
- To mitigate this, you must install the tirdad kernel module, which generates random ISNs for connections.
- Overall, alerting can be configured, logging can be set up, and audits can be performed.
- Based on pre-configured rules, Audit generates log entries to record as much information about the events that are happening on your system as possible.
- In my opinion, you should drop all non-industry policies, articles, manuals, and others especially on production environments and standalone home servers.
- Note that this usually requires high-performance HSMs for busy servers.
Deals with the particulars of installing and setting up a secure SUSE Linux Enterprise Server, and additional post-installation processes required to further secure and harden that installation. Supports the administrator with security-related choices and decisions. This procedure configures RELP on all hosts in the clients group in the Ansible inventory. The RELP configuration uses Transport Layer Security (TLS) to encrypt the message transmission for secure transfer of logs over the network. You can use an Ansible playbook with the logging System Role to configure logging on RHEL clients and transfer logs to a remote logging system using TLS encryption. When logging to disk or using a serial console is not possible, you can use the netconsole kernel module and the same-named service to log kernel messages over a network to a remote rsyslog service.
In this configuration, the SSS threshold t is set to 1 and the clevis luks bind command successfully reconstructs the secret if at least one from two listed tang servers is available. A profile is a set of rules based https://remotemode.net/ on a security policy, such as OSPP, PCI-DSS, and Health Insurance Portability and Accountability Act (HIPAA). This enables you to audit the system in an automated way for compliance with security standards.