CVE-2023-5541

Script execution via unescaped CSV preview cells

Published Nov 9, 2023 · Updated Aug 2, 2024

Cross-site scripting in Moodle LMS allows attackers to execute script in an importer's browser through a crafted grade CSV file. The grade/import/csv preview renderer places CSV headers and data cells into an HTML table without applying s() output escaping. Exploitation requires a Moodle user with grade-import access to preview an attacker-controlled spreadsheet, running the script in that user's session.

CVSS severity3.3
Low
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Moodle LMS allows attackers to execute script in an importer's browser through a crafted grade CSV file. The grade/import/csv preview renderer places CSV headers and data cells into an HTML table without applying s() output escaping. Exploitation requires a Moodle user with grade-import access to preview an attacker-controlled spreadsheet, running the script in that user's session.

The record

CVE
CVE-2023-5541
Published
Nov 9, 2023
Updated
Aug 2, 2024
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-79, T1204.002
Attack vector
local
Privileges
unauthenticated

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

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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=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 privilegesunauthenticated

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

3.3Fedora ProjectCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.002Malicious File

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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