CVE-2024-4789 is a Server-Side Request Forgery (SSRF) vulnerability identified in the Cost Calculator Builder PRO plugin for WordPress, developed by StylemixThemes. This vulnerability exists in all versions up to 3.1.72 and is triggered via the send_demo_webhook() function. SSRF vulnerabilities allow an attacker to abuse a server-side component to send HTTP requests to arbitrary domains or IP addresses, including internal network resources that are otherwise inaccessible externally. In this case, an authenticated attacker with subscriber-level privileges or higher can exploit the vulnerability without requiring additional user interaction. By leveraging this flaw, attackers can make the web application initiate requests to internal services, potentially leading to unauthorized information disclosure or modification of internal data. The vulnerability is rated with a CVSS 3.1 base score of 6.4, indicating a medium severity level. The vector metrics highlight that the attack can be performed remotely over the network (AV:N), requires low attack complexity (AC:L), needs privileges (PR:L), but no user interaction (UI:N), and impacts confidentiality and integrity with a scope change (S:C). No public exploits or patches are currently available, emphasizing the need for proactive mitigation. The vulnerability affects a popular WordPress plugin used globally, making it a relevant concern for many organizations relying on WordPress for their web presence.

The SSRF vulnerability in Cost Calculator Builder PRO can have significant impacts on organizations running vulnerable WordPress sites. Attackers with minimal privileges (subscriber-level) can exploit this flaw to send arbitrary HTTP requests from the web server to internal or external systems. This can lead to unauthorized access to internal services, potentially exposing sensitive information such as internal APIs, metadata services, or administrative interfaces not intended for public access. The ability to modify internal data via these requests can further escalate the impact, enabling attackers to alter configurations or inject malicious payloads. While the vulnerability does not directly affect availability, the compromise of confidentiality and integrity can lead to data breaches, lateral movement within internal networks, and ultimately full system compromise. Organizations relying on this plugin may face reputational damage, regulatory penalties, and operational disruptions if exploited. The medium CVSS score reflects the moderate but tangible risk, especially given the low privilege required and the widespread use of WordPress and this plugin.

To mitigate CVE-2024-4789, organizations should take the following specific actions: 1) Immediately identify and inventory all WordPress installations using the Cost Calculator Builder PRO plugin and determine their versions. 2) Apply any available patches or updates from StylemixThemes as soon as they are released. In the absence of official patches, consider temporarily disabling or uninstalling the plugin to eliminate the attack surface. 3) Restrict user privileges rigorously; limit subscriber-level accounts and review user roles to minimize the number of users who can exploit this vulnerability. 4) Implement network segmentation and firewall rules to restrict outbound HTTP requests from web servers, preventing unauthorized internal network access via SSRF. 5) Monitor web server logs and network traffic for unusual outbound requests, especially those targeting internal IP ranges or sensitive endpoints. 6) Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious requests to the vulnerable function. 7) Educate administrators and developers about SSRF risks and encourage secure coding practices to prevent similar vulnerabilities. These targeted measures go beyond generic advice by focusing on controlling the specific attack vector and limiting the potential for internal network exploitation.