CVE-2021-24159
CWE-352Published: April 5, 2021· Updated: Jun 17, 2026
Official Description
Due to the lack of sanitization and lack of nonce protection on the custom CSS feature, an attacker could craft a request to inject malicious JavaScript on a site using the Contact Form 7 Style WordPress plugin through 3.1.9. If an attacker successfully tricked a site’s administrator into clicking a link or attachment, then the request could be sent and the CSS settings would be successfully updated to include malicious JavaScript.
Technical Analysis
CVE-2021-24159 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-352)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-24159 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts