CVE-2021-24740Public exploitNetwork attack vector

Administrator-level stored XSS via unescaped settings attributes

Published Oct 18, 2021 · Updated Aug 3, 2024

Stored cross-site scripting in Themeum Tutor LMS before 1.9.9 allows remote authenticated users to execute script through crafted settings. The plugin stores values for the login-error message, lesson permalink base, YouTube API key, and email identity fields, then inserts them into HTML attributes without escaping. Administrator-level access is required, and the script executes in a browser when an affected settings page loads even if unfiltered_html is disabled.

CVSS severity5.5
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in Themeum Tutor LMS before 1.9.9 allows remote authenticated users to execute script through crafted settings. The plugin stores values for the login-error message, lesson permalink base, YouTube API key, and email identity fields, then inserts them into HTML attributes without escaping. Administrator-level access is required, and the script executes in a browser when an affected settings page loads even if unfiltered_html is disabled.

The record

CVE
CVE-2021-24740
Published
Oct 18, 2021
Updated
Aug 3, 2024
Vendor
Themeum
Product
Tutor LMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=1.9.9 <1.9.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Themeum · Tutor LMSversion=1.9.9 <1.9.9

Published CVSS scores

5.5WordfenceCVSS:3.1/AV:N/AC:L/PR:H/UI:N/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

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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