CVE-2021-24528Public exploitNetwork attack vector

Stored XSS via unsanitized SMTP settings

Published Aug 30, 2021 · Updated Aug 3, 2024

Stored cross-site scripting in WPManageNinja FluentSMTP before 2.0.1 allows remote authenticated users to run script in an administrator's browser. The fluentmail-post-settings action stores connection[sender_name] without sanitization, and the SMTP settings view outputs the value without escaping. A role capable of managing plugins must submit the setting, and script execution occurs when an administrator views the affected settings page.

CVSS severity5.4
Medium
EPSS probability0.62%
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 WPManageNinja FluentSMTP before 2.0.1 allows remote authenticated users to run script in an administrator's browser. The fluentmail-post-settings action stores connection[sender_name] without sanitization, and the SMTP settings view outputs the value without escaping. A role capable of managing plugins must submit the setting, and script execution occurs when an administrator views the affected settings page.

The record

CVE
CVE-2021-24528
Published
Aug 30, 2021
Updated
Aug 3, 2024
Vendor
WPManageNinja
Product
FluentSMTP
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 30, 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=2.0.1 <2.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

WPManageNinja · FluentSMTPversion=2.0.1 <2.0.1

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
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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