CVE-2021-43560Network attack vector

Unauthenticated calendar event disclosure

Published Nov 22, 2021 · Updated Aug 4, 2024

Information disclosure in Moodle LMS 3.11 through 3.11.3, 3.10 through 3.10.7, and 3.9 through 3.9.10 allows remote attackers to fetch other users' calendar action events. The calendar web-service endpoint performs insufficient capability checks before returning event data for another user. The request is read-only and requires access to the web service; impact is limited to confidentiality of calendar action events, with no reported modification or service interruption.

CVSS severity5.3
Medium
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Moodle LMS 3.11 through 3.11.3, 3.10 through 3.10.7, and 3.9 through 3.9.10 allows remote attackers to fetch other users' calendar action events. The calendar web-service endpoint performs insufficient capability checks before returning event data for another user. The request is read-only and requires access to the web service; impact is limited to confidentiality of calendar action events, with no reported modification or service interruption.

The record

CVE
CVE-2021-43560
Published
Nov 22, 2021
Updated
Aug 4, 2024
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-668, T1213
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=moodle 3.11.4, moodle 3.10.8 and moodle 3.9.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moodle · Moodle LMSversion=moodle 3.11.4, moodle 3.10.8 and moodle 3.9.11

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1213Data from Information Repositories

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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