CVE-2021-24278

published 2021-05-14

CVE-2021-24278: In the Redirection for Contact Form 7 WordPress plugin before 2.3.4, unauthenticated users can use the wpcf7r_get_nonce AJAX action to retrieve a valid nonce…

Priority P2 76 high 7.5 CVSS 3.1

AV N AC L PR N UI N S U C H I N A N

ITW EXPLOIT VulnCheck KEV

In the Redirection for Contact Form 7 WordPress plugin before 2.3.4, unauthenticated users can use the wpcf7r_get_nonce AJAX action to retrieve a valid nonce for any WordPress action/function.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
query_solutions	redirection_for_contact_form_7	>= 2.3.4 < 2.3.4	2.3.4
querysol	redirection_for_contact_form_7	< 2.3.4	2.3.4

Detection & IOCs extracted from sources · hover to see the quote

url /wp-admin/admin-ajax.php↗

other wpcf7r_get_nonce↗

• → Detect exploitation attempts by monitoring POST requests to /wp-admin/admin-ajax.php with the body parameter 'action=wpcf7r_get_nonce'. Unauthenticated requests containing this action indicate active exploitation. ↗
• → A successful exploitation response will contain both '"success":true' and a nonce value matching the pattern '"nonce":"[a-f0-9]+"' in the HTTP response body. ↗
• → The Content-Type header for the exploit request is 'application/x-www-form-urlencoded'. Monitor for unauthenticated POST requests to admin-ajax.php with this content type and the wpcf7r_get_nonce action. ↗

• · The vulnerability affects only the Redirection for Contact Form 7 WordPress plugin versions before 2.3.4. Sites running version 2.3.4 or later are not affected. ↗
• · The 'param' field in the POST body (e.g., 'param=wp_rest') controls which WordPress nonce is generated. Attackers can substitute any valid WordPress action/function name to obtain a nonce for it. ↗

CVSS provenance

nvd v3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd v2.0 5.0 MEDIUM AV:N/AC:L/Au:N/C:P/I:N/A:N

vulncheck 7.5 HIGH

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CWE-863