01. Wazuh: Strengths, Limitations & Key Deployment Considerations

1. Overview

Wazuh is an open‑source cybersecurity platform that combines SIEM and XDR functionality. It was created from OSSEC in 2015 and offers real‑time monitoring of logs, file integrity checks, rootkit detection, behavioral analytics, and automated incident response across Linux, Windows, macOS, containers, and cloud environments.

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✅ Strengths

• Fully open source and free

Wazuh is completely free to use — no licensing fees or vendor lock-in. It benefits from a global community actively contributing rules, decoders, plugins, and integrations.

• Integrated SIEM + XDR capabilities

Besides collecting logs, Wazuh ingests threat intelligence, detects anomalous behaviors, and supports automated actions through Active Response—all within one platform.

• Extensive rule set and use cases

Includes over 3,000 prebuilt rules and decoders categorized by severity level (0–16). It’s capable of detecting SSH brute force, ransomware behavior, privilege escalation, PowerShell misuse, malware execution, and more. Administrators can also create custom ruless and trigger automated responses such as blocking IP addresses or restarting services.

• Flexible integration ecosystem

Wazuh integrates seamlessly with analytics platforms like Elastic Stack, OpenSearch, or Splunk, and supports ingestion of IoCs from external intelligence sources. Alerts can be routed to Slack, Telegram, PagerDuty, JIRA, or orchestrated through automation tools.

• Asset inventory and vulnerability detection

Wazuh agents collect detailed host data—including installed software, open ports, and configuration—and check against vulnerability databases (such as CVE/NVD), helping organizations maintain compliance (e.g. PCI‑DSS, ISO).

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⚠️ Limitations & Constraints

• Does not index all logs by default

By default, Wazuh indexes only alert-triggering logs. Other events are stored in archive files and not indexed unless specifically configured (logall_json option). Full event logging requires additional steps to enable indexing and dashboard visibility.

• No automatic log cleanup

Wazuh does not delete old logs on its own. Administrators must implement log rotation or retention policies using tools like cronjobs or Elasticsearch’s Index Lifecycle Management (ILM). Without these, logs accumulate and can degrade performance.

• High resource usage at scale

Processing high volumes of log data and managing large numbers of agents requires significant hardware resources (CPU, RAM, disk I/O). Scaling may involve multi-node indexing and careful infrastructure planning.

• Steep learning curve

Initial setup and tuning (like writing custom rules or configuring log retention) require advanced system administration knowledge. Fine‑tuning takes time and familiarity with both Wazuh and its underlying stack.

• No premium threat intelligence out of the box

Wazuh does not include built-in commercial threat intelligence feeds. Users must actively ingest and manage their own external feeds to enhance detection capability.

• Interface may need customization

While functional, the default Wazuh dashboard can feel less intuitive compared to commercial SIEM tools. Some environments require advanced customization for intuitive reporting and dashboards.

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🔎 Deployment Considerations

• Ensure a skilled technical team is available (SOC engineers or sysadmins familiar with Wazuh, Elastic/OpenSearch, and log management).

• Plan infrastructure capacity based on anticipated log volume, number of agents, and retention duration.

• Enable logall_json if full event logging is required, and configure indexing accordingly.

• Customize rule severity and filters to reduce false positives and noise.

• Test Active Response actions thoroughly to prevent unintended disruptions.

• Map detection and compliance needs (e.g. PCI‑DSS, NIST frameworks) to appropriate rule sets.

• Integrate high-quality external threat intelligence sources and keep them updated.

Final Thoughts

Wazuh is an excellent option for any organization looking for robust security monitoring and response capabilities without license costs. With proper infrastructure and skilled personnel, it can deliver enterprise-grade detection and response functionality. However, to fully utilize its potential, consider the complexities of log indexing, retention, scalability, and tuning.