CVE-2021-24219: The Thrive Optimize WordPress plugin before 1.4.13.3, Thrive Comments WordPress plugin before 1.4.15.3, Thrive Headline Optimizer WordPress plugin before…

PriorityP179medium5.3CVSS 3.1

AVNACLPRNUINSUCNILAN

ITWEXPLOITVulnCheck KEV

Exploited in the wild

EPSS

2.08%

79.1th percentile

The Thrive Optimize WordPress plugin before 1.4.13.3, Thrive Comments WordPress plugin before 1.4.15.3, Thrive Headline Optimizer WordPress plugin before 1.3.7.3, Thrive Leads WordPress plugin before 2.3.9.4, Thrive Ultimatum WordPress plugin before 2.3.9.4, Thrive Quiz Builder WordPress plugin before 2.3.9.4, Thrive Apprentice WordPress plugin before 2.3.9.4, Thrive Visual Editor WordPress plugin before 2.6.7.4, Thrive Dashboard WordPress plugin before 2.3.9.3, Thrive Ovation WordPress plugin before 2.4.5, Thrive Clever Widgets WordPress plugin before 1.57.1 and Rise by Thrive Themes WordPress theme before 2.0.0, Ignition by Thrive Themes WordPress theme before 2.0.0, Luxe by Thrive Themes WordPress theme before 2.0.0, FocusBlog by Thrive Themes WordPress theme before 2.0.0, Minus by Thrive Themes WordPress theme before 2.0.0, Squared by Thrive Themes WordPress theme before 2.0.0, Voice WordPress theme before 2.0.0, Performag by Thrive Themes WordPress theme before 2.0.0, Pressive by Thrive Themes WordPress theme before 2.0.0, Storied by Thrive Themes WordPress theme before 2.0.0, Thrive Themes Builder WordPress theme before 2.2.4 register a REST API endpoint associated with Zapier functionality. While this endpoint was intended to require an API key in order to access, it was possible to access it by supplying an empty api_key parameter in vulnerable versions if Zapier was not enabled. Attackers could use this endpoint to add arbitrary data to a predefined option in the wp_options table.

Affected

42 ranges· showing 25

Vendor	Product	Version range	Fixed in
thrive_themes	focusblog_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	ignition_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	luxe_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	minus_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	performag_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	pressive_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	rise_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	squared_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	storied_by_thrive_themes	>= 2.0.0 < 2.0.0	2.0.0
thrive_themes	thrive_apprentice	>= 2.3.9.4 < 2.3.9.4	2.3.9.4
thrive_themes	thrive_clever_widgets	>= 1.57.1 < 1.57.1	1.57.1
thrive_themes	thrive_comments	>= 1.4.15.3 < 1.4.15.3	1.4.15.3
thrive_themes	thrive_dashboard	>= 2.3.9.3 < 2.3.9.3	2.3.9.3
thrive_themes	thrive_headline_optimizer	>= 1.3.7.3 < 1.3.7.3	1.3.7.3
thrive_themes	thrive_leads	>= 2.3.9.4 < 2.3.9.4	2.3.9.4
thrive_themes	thrive_optimize	>= 1.4.13.3 < 1.4.13.3	1.4.13.3
thrive_themes	thrive_ovation	>= 2.4.5 < 2.4.5	2.4.5
thrive_themes	thrive_quiz_builder	>= 2.3.9.4 < 2.3.9.4	2.3.9.4
thrive_themes	thrive_themes_builder	>= 2.2.4 < 2.2.4	2.2.4
thrive_themes	thrive_ultimatum	>= 2.3.9.4 < 2.3.9.4	2.3.9.4
thrive_themes	thrive_visual_editor	>= 2.6.7.4 < 2.6.7.4	2.6.7.4
thrive_themes	voice	>= 2.0.0 < 2.0.0	2.0.0
thrivethemes	focusblog	< 2.0.0	2.0.0
thrivethemes	ignition	< 2.0.0	2.0.0
thrivethemes	luxe	< 2.0.0	2.0.0

Detection & IOCsextracted from sources · hover to see the quote

url/wp-json/td/v1/optin/subscription↗

commandPOST /wp-json/td/v1/optin/subscription HTTP/1.1 Host: {{Hostname}} Content-Type: application/x-www-form-urlencoded hook_url={"http:\/\/key":"{{filename}}.php"}&api_key=

othertd_optin_webhook

→Look for unauthenticated POST requests to the REST API endpoint /wp-json/td/v1/optin/subscription with an empty api_key parameter, which indicates exploitation of CVE-2021-24219.
→Detect exploitation by monitoring for the string 'td_optin_webhook' in HTTP response bodies from the Zapier REST endpoint, confirming the option write succeeded.
→Monitor wp_options table for unexpected or arbitrary data insertions, particularly entries associated with the Zapier/optin webhook functionality (td_optin_webhook).
→Flag POST requests to /wp-json/td/v1/optin/subscription where the body contains hook_url with a .php filename and api_key is empty, as this matches the known attack payload pattern.

·The vulnerability is only exploitable when Zapier integration is NOT enabled on the target site; if Zapier is enabled, the API key check is enforced and the endpoint is not accessible without a valid key.

CVSS provenance

nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N

vulncheck5.3MEDIUM

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