CVE intelligence and bounded remediation

CVE-2021-43584 — Nagios Nagios Cross Platform Agent security vulnerability

Medium CVSS 4.8

DOM-based Cross Site Scripting (XSS vulnerability in 'Tail Event Logs' functionality in Nagios Nagios Cross-Platform Agent (NCPA) before 2.4.0 allows attackers to run arbitrary code via the name element when filtering for a log.

Severity
Medium
CVSS
4.8 (3.1)
Published
2024-01-24
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • nagios / nagios_cross_platform_agent

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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