CVE-2023-5550

Remote code execution via message processor path traversal

Published Nov 9, 2023 · Updated Aug 2, 2024

Code injection in affected Moodle LMS releases allows remote authenticated users with direct server access to execute arbitrary PHP code. The message settings fragment uses an insufficiently filtered processor type to build a path that include_once loads beneath message/output. Exploitation requires misconfigured shared hosting that exposes another tenant's files, allowing a Moodle user to place PHP outside the webroot and traverse to it.

CVSS severity6.5
Medium
EPSS probability1.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in affected Moodle LMS releases allows remote authenticated users with direct server access to execute arbitrary PHP code. The message settings fragment uses an insufficiently filtered processor type to build a path that include_once loads beneath message/output. Exploitation requires misconfigured shared hosting that exposes another tenant's files, allowing a Moodle user to place PHP outside the webroot and traverse to it.

The record

CVE
CVE-2023-5550
Published
Nov 9, 2023
Updated
Aug 2, 2024
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-94, T1190
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <3.9.24
  2. Affected versionversion=3.11.0 <3.11.17
  3. Affected versionversion=4.0.0 <4.0.11
  4. Affected versionversion=4.1.0 <4.1.6
  5. Affected versionversion=4.2.0 <4.2.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Moodle · Moodle LMSversion=0 <3.9.24; version=3.11.0 <3.11.17; version=4.0.0 <4.0.11; version=4.1.0 <4.1.6; version=4.2.0 <4.2.3

Published CVSS scores

6.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
9.8GitLab Advisory DatabaseCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
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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