CVE-2022-40314Network attack vector

Code execution via legacy-backup deserialization

Published Sep 30, 2022 · Updated May 20, 2025

Unsafe deserialization in affected Moodle LMS releases allows attackers to execute code through a crafted Moodle 1.9 backup. The convert_configdata() method in blocks/html/backup/moodle1/lib.php decodes attacker-controlled configdata and passes the serialized object to PHP unserialize(). Processing the crafted file through a permission-controlled course restore is required; successful exploitation runs attacker-supplied code in the Moodle server process.

CVSS severity9.8
Critical
EPSS probability1.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in affected Moodle LMS releases allows attackers to execute code through a crafted Moodle 1.9 backup. The convert_configdata() method in blocks/html/backup/moodle1/lib.php decodes attacker-controlled configdata and passes the serialized object to PHP unserialize(). Processing the crafted file through a permission-controlled course restore is required; successful exploitation runs attacker-supplied code in the Moodle server process.

The record

CVE
CVE-2022-40314
Published
Sep 30, 2022
Updated
May 20, 2025
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 30, 2022CVE publishedPublication date reported by the CVE source.
  2. May 20, 2025Record 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=4.0 to 4.0.3, 3.11 to 3.11.9, 3.9 to 3.9.16 and earlier unsupported versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moodle · Moodle LMSversion=4.0 to 4.0.3, 3.11 to 3.11.9, 3.9 to 3.9.16 and earlier unsupported versions

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

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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