CVE-2021-24134 - CVE House
Back to Database
Status published Medium CVE-2021-24134

Constant Contact Forms < 1.8.8 - Multiple Authenticated Stored XSS

Vulnerability Description

Unvalidated input and lack of output encoding in the Constant Contact Forms WordPress plugin, versions before 1.8.8, lead to multiple Stored Cross-Site Scripting vulnerabilities, which allowed high-privileged user (Editor+) to inject arbitrary JavaScript code or HTML in posts where the malicious form is embed.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2021-24134

Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Nguyen Anh Tien - SunCSR (Sun* Cyber Security Research)

References

More from Unknown

View All →
CVE-2025-9978
Jeg Elementor Kit < 2.7.0 - Author+ Stored XSS
Unknown 0
CVE-2025-9959
Sandbox escape in smolagents Local Python execution environment via dunder attributes
High 7.6
CVE-2025-9900
Libtiff: libtiff write-what-where
High 8.8
CVE-2025-9784
Undertow: undertow madeyoureset http/2 ddos vulnerability
High 7.5
CVE-2025-9710
Responsive Lightbox & Gallery < 2.5.3 - Unauthenticated Stored-XSS via Comments
Unknown 0

Affected Vendor

Affected Software

Constant Contact Forms
Vulnerable Versions:
1.8.8

Timeline

Official Publish: March 18th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Weaknesses (CWE)

CWE-79

MITRE ATT&CK TTPs

T1189 Drive-by Compromise
Initial Access
T1059.007 JavaScript
Execution
T1539 Steal Web Session Cookie
Collection
T1213 Data from Information Repositories
Collection
T1567 Exfiltration Over Web Service
Exfiltration
T1491.001 Defacement
Impact