CVE-2021-21809 Moodle command execution vulnerability exists in the default legacy spellchecker plugin
An administrator can execute arbitrary commands via the legacy spellchecker plugin in Moodle.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-21809?
CVE-2021-21809 is a high-severity command injection vulnerability in Moodle Moodle, published on 23 Jun 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-78
Which versions are affected by CVE-2021-21809?
3 open source packages ship an affected version, including moodle/moodle and moodle. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
moodle/moodle Packagist | All versions | None |
moodle/moodle Packagist | All versions | None |
moodle Bitnami | From 3.10.0 | 3.10.1 |
Products include Moodle Moodle.
How do I fix CVE-2021-21809?
Apply the vendor's patch.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2021-21809 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21809 exists.
Public exploit code: 1 Metasploit module and 1 proofs of concept on GitHub.
Other vulnerabilities in Moodle Moodle
- CVE-2006-4935 File upload in n/a
- CVE-2006-4936 Moodle does not properly validate module instance id
- CVE-2004-2233 Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors.
- CVE-2004-2235 Cross-site scripting in n/a
- CVE-2004-2236 Other in n/a
Sources
Also known as BIT-moodle-2021-21809, GHSA-c7jj-vfmr-j9mj, UBUNTU-CVE-2021-21809.