CVE-2021-24245Public exploitNetwork attack vector

Unauthenticated reflected XSS via unescaped attribute input

Published May 5, 2021 · Updated Aug 3, 2024

Cross-site scripting in Stop Spammers before 2021.9 allows remote attackers to execute script in a victim browser via crafted login input. When the plugin blocks a request, it places the supplied spam-matching value into an HTML attribute after only stripping tags, so quotes and event-handler syntax remain executable. Exploitation requires a victim to submit or follow a request that reaches the blocking response; the documented impact is browser-side script execution in the site’s origin, with no evidence of direct server compromise.

CVSS severity6.1
Medium
EPSS probability5.72%
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 Stop Spammers before 2021.9 allows remote attackers to execute script in a victim browser via crafted login input. When the plugin blocks a request, it places the supplied spam-matching value into an HTML attribute after only stripping tags, so quotes and event-handler syntax remain executable. Exploitation requires a victim to submit or follow a request that reaches the blocking response; the documented impact is browser-side script execution in the site’s origin, with no evidence of direct server compromise.

The record

CVE
CVE-2021-24245
Published
May 5, 2021
Updated
Aug 3, 2024
Vendor
Trumani
Product
Stop Spammers
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 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=2021.9 <2021.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Trumani · Stop Spammersversion=2021.9 <2021.9

Published CVSS scores

6.1AtomicorpCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Cross-site Scripting (XSS)
T1189Drive-by Compromise

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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