CVE-2021-24828Public exploitNetwork attack vector

Stored script execution via unescaped shortcode attributes

Published Jan 3, 2022 · Updated Aug 3, 2024

Stored cross-site scripting in MLCALC Mortgage Loan Calculator before 1.5.17 allows remote authenticated users to execute script in browsers. The mlcalc shortcode renders its schedule attribute without output escaping, allowing a crafted contributor-supplied value to become executable JavaScript. Contributor access is sufficient to store the payload, but another user must view the resulting page for execution in that user's browser context.

CVSS severity5.4
Medium
EPSS probability0.60%
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 MLCALC Mortgage Loan Calculator before 1.5.17 allows remote authenticated users to execute script in browsers. The mlcalc shortcode renders its schedule attribute without output escaping, allowing a crafted contributor-supplied value to become executable JavaScript. Contributor access is sufficient to store the payload, but another user must view the resulting page for execution in that user's browser context.

The record

CVE
CVE-2021-24828
Published
Jan 3, 2022
Updated
Aug 3, 2024
Vendor
MLCALC
Product
Mortgage Loan Calculator
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 3, 2022CVE 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

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=1.5.17 <1.5.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MLCALC · Mortgage Loan Calculatorversion=1.5.17 <1.5.17

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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')
T1059.007Command and Scripting Interpreter: JavaScript

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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