CVE-2021-37344
CRITICALCVE-2021-37344 is a critical-severity (CVSS 9.8) OS Command Injection vulnerability in nagios nagios xi switch wizard. EPSS puts its 30-day exploitation probability at 96.8% (100th percentile). O3 Security detects and blocks CVE-2021-37344 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
Nagios XI Switch Wizard before version 2.5.7 is vulnerable to remote code execution through improper neutralisation of special elements used in an OS Command (OS Command injection).
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-37344 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 372,324 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Description
Nagios XI Switch Wizard before version 2.5.7 is vulnerable to remote code execution through improper neutralisation of special elements used in an OS Command (OS Command injection).
Affected Products
nagios xi switch wizardnagiosDetection & mitigation playbook
Vendor / applianceDetect
Inventory every nagios nagios xi switch wizard deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the nagios nagios xi switch wizard security patch or hotfix for CVE-2021-37344 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2021-37344 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2021-37344. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-37344 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-37344 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.