CVE-2021-21809 : A command execution vulnerability exists in the default legacy spellchecker plug

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.

Published 2021-06-23 22:15:08

Updated 2022-08-24 19:43:50

Source Talos

View at NVD, CVE.org

Products affected by CVE-2021-21809

Moodle » Moodle » Version: 3.10.0
cpe:2.3:a:moodle:moodle:3.10.0:-:*:*:*:*:*:*
Matching versions

Exploit prediction scoring system (EPSS) score for CVE-2021-21809

EPSS FAQ

5.12%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 93 %

Percentile, the proportion of vulnerabilities that are scored at or less

Metasploit modules for CVE-2021-21809

Moodle SpellChecker Path Authenticated Remote Command Execution

Disclosure Date: 2021-06-22

First seen: 2022-12-23

exploit/multi/http/moodle_spelling_path_rce

Moodle allows an authenticated administrator to define spellcheck settings via the web interface. An administrator can update the aspell path to include a command injection. This is extremely similar to CVE-2013-3630, just using a different variable. This mo

More information

CVSS scores for CVE-2021-21809

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
9.0	HIGH	AV:N/AC:L/Au:S/C:C/I:C/A:C	8.0	10.0	NIST
Access Vector: Network Access Complexity: Low Authentication: Single Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: Complete
8.2	HIGH	CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:L	2.3	5.3	Talos
Attack Vector: Network Attack Complexity: Low Privileges Required: High User Interaction: None Scope: Changed Confidentiality: High Integrity: Low Availability: Low
9.1	CRITICAL	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H	2.3	6.0	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: High User Interaction: None Scope: Changed Confidentiality: High Integrity: High Availability: High

CWE ids for CVE-2021-21809

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2021-21809

http://packetstormsecurity.com/files/164481/Moodle-SpellChecker-Path-Authenticated-Remote-Command-Execution.html

Moodle SpellChecker Path Authenticated Remote Command Execution ≈ Packet Storm
Exploit;Third Party Advisory;VDB Entry
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1277

TALOS-2021-1277 || Cisco Talos Intelligence Group - Comprehensive Threat Intelligence
Third Party Advisory;Exploit

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