CVE-2021-25083Public exploitNetwork attack vector

Reflected XSS via unescaped qtype attribute output

Published Jan 24, 2022 · Updated Aug 3, 2024

Reflected XSS in Registrations for the Events Calendar before 2.7.10 allows remote attackers to run script via a crafted qtype value. The settings page writes qtype into an HTML attribute without contextual escaping, so a quotation mark can terminate the value and add an event handler. Exploitation requires an authenticated user with settings-page access to follow the crafted URL; the script then runs in the site origin with that user's session.

CVSS severity6.1
Medium
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Registrations for the Events Calendar before 2.7.10 allows remote attackers to run script via a crafted qtype value. The settings page writes qtype into an HTML attribute without contextual escaping, so a quotation mark can terminate the value and add an event handler. Exploitation requires an authenticated user with settings-page access to follow the crafted URL; the script then runs in the site origin with that user's session.

The record

CVE
CVE-2021-25083
Published
Jan 24, 2022
Updated
Aug 3, 2024
Vendor
Roundup WP
Product
Registrations for the Events Calendar
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 24, 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

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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=2.7.10 <2.7.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Roundup WP · Registrations for the Events Calendarversion=2.7.10 <2.7.10

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NVDCVSS: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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

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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