# CVE-2021-24498: Calendar Event Multi View - XSS

> Live exploitation tracking for CVE-2021-24498 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2021-24498

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 6.1
- **Public exploit available:** Yes
- **Affected products:** N/A Calendar Event Multi View
- **Weaknesses:** CWE-79 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'))
- **Tags:** cms, wordpress

## Description

The Calendar Event Multi View WordPress plugin before 1.4.01 does not sanitise or escape the 'start' and 'end' GET parameters before outputting them in the page (via php/edit.php), leading to a reflected Cross-Site Scripting issue.

## CrowdSec analysis

[CVE-2021-24498](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-24498) is a vulnerability affecting the Calendar Event Multi View WordPress plugin, where improper handling of input allows attackers to inject arbitrary web content via reflected cross-site scripting.

CrowdSec has been tracking this vulnerability and its exploits since 7th of April 2025.

CrowdSec network observations suggest that most exploitation of CVE-2021-24498 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental.
CrowdSec network telemetry also shows that exploitation of CVE-2021-24498 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Exploitation attempts commonly involve URLs with `/` that include parameter sequences related to `cpmvc_id=1&cpmvc_do_action=mvparse&f=edit`, with further manipulation of date-related parameters.

## Timeline

- 2021-08-02: CVE Published. CVE-2021-24498 is published to NVD.
- 2025-04-07: Rule Released. CrowdSec releases a rule to detect CVE-2021-24498 exploitation attempts against the CrowdSec Network.
- 2025-04-07: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-24498 for the first time.

## References

- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-24498.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-24498) follows observed exploitation activity for CVE-2021-24498. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.