Disable the Root User from Logging in to the System Using SSH

The PermitRootLogin parameter in the SSH configuration file /etc/ssh/sshdconfig specifies whether the root user can log in to the system using SSH. The root user is not allowed to log in to the system using SSH. System administrators must use their own user to log in to the system using SSH and r...

Configure a Proper Value for audit_backlog_limit

auditbackloglimit sets the buffer queue length for audit events awaiting transfer to the audit service. The default value is 64. If the queue is full, audit events are discarded and an alarm log is generated, indicating that the queue is full. If the value is too small, audit events may be lost. ...

Configure Audit Rules for File Access Failures

System calls, such as open, truncate, ftruncate, create and openat, are audited and monitored. If the -EACCES or -EPERM error is returned, you lack the permission to access the files. In this case, audit logs need to be recorded. File access failures due to a lack of proper permissions are common...

Ensure That auditd Is Enabled

The auditd component is a user-space component of the Linux audit framework, providing the auditctl, ausearch, and aureport programs to audit and view logs. Audit rules are configured using the auditctl program. When getting started, auditctl reads these rules from /etc/audit/audit.rules. The aud...

Correctly Configure the Log Records of Each Service

Logs should be configured so that important system behaviors and security-related information are recorded by rsyslog. The configuration files /etc/rsyslog.conf and /etc/rsyslog.d/.conf specify the rules for logging and the files for recording specific types of logs. If logging is not configured,...

Configure Dumping journald Logs for rsyslog

The system uses journald to collect logs. Logs may be stored on volatile or persistent storage devices. As a result, logs may be lost or the drive space may be used up. In this case, logs need to be dumped in a timely manner to ensure the security of logs and the system. SPDX-FileCopyrightText:...

Configure Audit Rules for File Deletion

Generally, it is highly risky to delete files in the OS. Misoperations by administrators or attacks may cause severe system faults. You are advised to audit and monitor system calls, such as rename, unlink, unlinkat, and renameat, and record deletion operation logs. Deleting system or service fil...

Configure the SSH Service Log Level Properly

SSH provides multiple log output levels, such as QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. A higher log level such as QUIET or FATAL prints less log information. This saves drive space but hinders administrators from auditing and tracing SSH events. Conversely, a lowe...

Configure Audit Rules for Network Environment

Attackers may change the system domain name and host name to launch attacks, such as host spoofing. It is recommended that the user set the audit of system calls setdomainname and sethostname and the audit of the /etc/hosts file to monitor changes in the system domain name and host name. You can...

Configure Audit Rules for Privilege-Escalated Commands

Users can call privilege-escalated commands that is, commands with SUID/SGID bits to obtain the super administrator permissions. This operation is risky and often exploited by attackers. You are advised to audit and monitor privilege-escalated commands for future tracing. By default, audit rules...

Configure Audit Rules for Kernel Module Changes

Generally, for deployed services, the loaded kernel modules do not change. Therefore, changes in loaded kernel modules may indicate attacks. You are advised to audit and monitor kernel module changes for future tracing. By default, audit rules for kernel module changes are not configured in...

Configure Audit Rules for File Access Control Permissions

File access permission control is the basic permission management in Linux. Different users can access different files after being authorized. This prevents sensitive information leakage or file data tampering between users and prevents common users from accessing high-permission files or...

Configure Audit Rules for Privilege Escalation Operations

In openEuler, logs of privilege escalation operations using the sudo command are recorded in the /var/log/secure file by default. This file also records other authentication-related security logs. If you want to audit privilege escalation operations using sudo, you are advised to record logs...

Configure Audit Rules for File System Mounting

Generally, for deployed services, the file system mounting does not change. Therefore, any change in the file system mounting may indicate attacks. For file systems with changes in mounting, audit and monitor their mounting conditions for tracing. By default, audit rules for file system mounting...

Configure sudoers Audit Rules

The sudo command allows common users to perform privileged operations as the root user, which is highly risky. Though attackers cannot access the root user easily, they can escalate the privilege using the sudo command. You are advised to configure audit for the /etc/sudoers file and the...

Ensure That Rotation Is Enabled for Audit Logs

maxlogfileaction decides the action taken when the size of a log file reaches the upper limit. By default, ROTATE is configured in openEuler, indicating that a new log file is created when the size of a log file reaches the upper limit and the original log file is not deleted. numlogs specifies t...

Information Exposure

Overview Affected versions of this package are vulnerable to Information Exposure when validating malformed payloads in the Validate function used by the KV v2 plugin. If payloads containing secrets are sent in creation or update requests to the REST API and caught by the validator, their content...

CVE-2025-4166

Vault Community and Vault Enterprise Key/Value kv Version 2 plugin may unintentionally expose sensitive information in server and audit logs when users submit malformed payloads during secret creation or update operations via the Vault REST API. This vulnerability, identified as CVE-2025-4166, is...

CVE-2025-4166

Vault Community and Vault Enterprise Key/Value kv Version 2 plugin may unintentionally expose sensitive information in server and audit logs when users submit malformed payloads during secret creation or update operations via the Vault REST API. This vulnerability, identified as CVE-2025-4166, is...

Modeling Behavioral Preferences of Cyber Adversaries Using Inverse Reinforcement Learning

This paper presents a holistic approach to attacker preference modeling from system-level audit logs using inverse reinforcement learning IRL. Adversary modeling is an important capability in cybersecurity that lets defenders characterize behaviors of potential attackers, which enables attributio...