CVE-2023-7065 in Stop Spammers Security Plugin
Summary
by MITRE • 05/04/2024
The Stop Spammers Security | Block Spam Users, Comments, Forms plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2024.4. This is due to missing or incorrect nonce validation on the sfs_process AJAX action. This makes it possible for unauthenticated attackers to add arbitrary IPs to the plugin's allowlist and blocklist via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 06/11/2026
The Stop Spammers Security plugin for WordPress represents a critical security vulnerability through its implementation of cross-site request forgery protection mechanisms. This vulnerability affects all versions up to and including 2024.4, making it a persistent threat across multiple releases. The flaw manifests specifically within the sfs_process AJAX action where proper nonce validation is either entirely absent or incorrectly implemented, creating a fundamental security gap in the plugin's access control measures.
The technical exploitation of this CSRF vulnerability occurs through the manipulation of the plugin's allowlist and blocklist functionality. An unauthenticated attacker can craft malicious requests that, when executed through a victim administrator's browser session, will add arbitrary IP addresses to either the allowlist or blocklist. This represents a significant compromise of the plugin's core security functionality, as the attacker can effectively modify the plugin's behavior without proper authentication or authorization. The vulnerability leverages the trust relationship between the administrator's browser and the WordPress site, making it particularly dangerous because the victim administrator is typically an authenticated user with elevated privileges.
The operational impact of this vulnerability extends beyond simple access control manipulation. By adding malicious IP addresses to the allowlist, an attacker could potentially bypass security measures and gain unauthorized access to the site's restricted areas. Conversely, adding legitimate IP addresses to the blocklist could cause legitimate users to be denied access to the site, creating service disruption and potential denial of service conditions. The attack vector requires social engineering to trick administrators into clicking malicious links, but once successful, the consequences are severe and can persist until the plugin is updated or the malicious entries are manually removed.
This vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in software applications. The implementation failure in nonce validation demonstrates a fundamental flaw in the plugin's security architecture that violates standard web application security practices. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and persistence within the target environment, as attackers can manipulate the plugin's configuration to maintain access or disrupt legitimate user access. The vulnerability also relates to T1566, which covers social engineering tactics, since successful exploitation requires administrator interaction through deceptive means.
The recommended mitigation strategies include immediate plugin updates to versions that address the nonce validation issue, implementation of additional security controls such as CAPTCHA verification for administrative actions, and network-level monitoring to detect suspicious pattern changes in allowlist and blocklist modifications. Administrators should also implement principle of least privilege for plugin management functions and consider using security headers such as Content Security Policy to limit potential exploitation vectors. Regular security auditing of WordPress plugins and maintaining updated security practices remain essential defensive measures against similar vulnerabilities in the WordPress ecosystem.