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Moodle Client side denial of service via personal message

Moderate severity GitHub Reviewed Published May 24, 2022 to the GitHub Advisory Database • Updated Apr 23, 2024

Package

composer moodle/moodle (Composer)

Affected versions

>= 3.5, < 3.5.16
>= 3.8, < 3.8.7
>= 3.9, < 3.9.4
>= 3.10, < 3.10.1

Patched versions

3.5.16
3.8.7
3.9.4
3.10.1

Description

It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that messaging did not impose a character limit when sending messages, which could result in client-side (browser) denial of service for users receiving very large messages.

References

Published by the National Vulnerability Database Jan 28, 2021
Published to the GitHub Advisory Database May 24, 2022
Reviewed Apr 23, 2024
Last updated Apr 23, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS score

0.092%
(40th percentile)

Weaknesses

CVE ID

CVE-2021-20185

GHSA ID

GHSA-c3j6-33r4-89q3

Source code

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