CVE-2021-24813

Events Made Easy <= 2.2.23 - Admin+ Stored Cross-Site Scripting

2021-10-04 00:00

Strategic Overview

Status: Patched in 2.2.24
Affected Plugin: Events Made Easy
Affected Version: < 2.2.24
CVSS: 5.5Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24813

View all Events Made Easy vulnerabilities

At a glance

CVE-2021-24813 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Events Made Easy WordPress plugin, affecting versions < 2.2.24. It carries a CVSS score of 5.5 (reachable over the network; low attack complexity). The issue is fixed in version 2.2.24; sites on affected versions should update now. Disclosed October 2021, reported by Huy Nguyen.

Vulnerability Overview

The Events Made Easy WordPress plugin before 2.2.24 does not sanitise and escape Custom Field Names, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Events Made Easy < 2.2.24 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Events Made Easy the fix is 2.2.24: builds < 2.2.24 are affected, anything from 2.2.24 onward is not.

Remediation

Update to version 2.2.24, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Events Made Easy: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Events Made Easy 2.2.24 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24813 https://www.wordfence.com/threat-intel/vulnerabilities/id/9a4488c8-7138-4046-88ea-84f9462eec93 https://nvd.nist.gov/vuln/detail/CVE-2021-24813

Related records

Same weakness class

Other vulnerabilities in Events Made Easy

CVSS Vector

5.5

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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