Skip to main content

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVE-2021-21809

High
9.1/10

Summary

A command execution vulnerability exists in the default legacy spellchecker plugin in Moodle. A specially crafted series of HTTP requests can lead to command execution. An attacker must have administrator privileges to exploit this vulnerabilities. This vulnerability affects Moodle 3.11.2, 3.10.0, and 3.8.0 versions.

  • LOW
  • NETWORK
  • HIGH
  • CHANGED
  • NONE
  • HIGH
  • HIGH
  • HIGH

CWE-78 - OS Command Injection

The OS command injection weakness (also known as shell injection) is a vulnerability which enables an attacker to run arbitrary OS commands on a server. This is done by modifying the intended downstream OS command and injecting arbitrary commands, enabling the execution of unauthorized OS commands. This has the potential to fully compromise the application along with all of its data, and, if the compromised process does not follow the principle of least privileges, it may compromise other parts of the hosting infrastructure as well. This weakness is listed as number ten in the 'CWE Top 25 Most Dangerous Software Weaknesses'.

References

Advisory Timeline

  • Published