CVE-2021-43559Network attack vector

Related-badge deletion via missing sesskey validation

Published Nov 22, 2021 · Updated Aug 4, 2024

CSRF 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 delete related-badge links. The removal branch in badges/related_action.php calls delete_related_badge() without validating a sesskey tied to the user's session. A victim with the configuredetails capability must hold an active session and submit the crafted request; the bounded consequence is deletion of a badge relationship.

CVSS severity8.8
High
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF 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 delete related-badge links. The removal branch in badges/related_action.php calls delete_related_badge() without validating a sesskey tied to the user's session. A victim with the configuredetails capability must hold an active session and submit the crafted request; the bounded consequence is deletion of a badge relationship.

The record

CVE
CVE-2021-43559
Published
Nov 22, 2021
Updated
Aug 4, 2024
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-352, CAPEC-62
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

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-352Cross-Site Request Forgery (CSRF)
CAPEC-62Cross Site Request Forgery

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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