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Case File

CVE-2021-21809

CRITICAL · CVSS 9.1 EPSS 24.17% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-06-23 · Last synced 2026-08-04

CyberRota Analysis

This is a critical severity vulnerability with a CVSS score of 9.1. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 24.2% probability of exploitation in the next 30 days.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit
External Security References

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-21809
Severity
CRITICAL
CVSS
9.1
EPSS
24.17%

Original NVD Description

A command execution vulnerability exists in the default legacy spellchecker plugin in Moodle 3.10. A specially crafted series of HTTP requests can lead to command execution. An attacker must have administrator privileges to exploit this vulnerabilities.

Related CVEs

Other vulnerabilities affecting the same vendor(s)