CVE-2024-13879 is a Server-Side Request Forgery (SSRF) vulnerability identified in the Stream plugin for WordPress, developed by xwp. The vulnerability exists in all versions up to and including 4.0.2, specifically within the webhook feature of the plugin. The root cause is insufficient validation of URLs or endpoints that the webhook functionality can access, allowing an authenticated attacker with administrator-level privileges or higher to craft requests that the server executes internally. SSRF vulnerabilities enable attackers to make the server send HTTP requests to arbitrary internal or external resources, potentially bypassing network access controls. In this case, the attacker can query internal services that are not directly accessible externally, and potentially modify data on those services if they accept such requests. The vulnerability requires the attacker to have high privileges (administrator or above) on the WordPress site, which limits exploitation to insiders or compromised admin accounts. The CVSS 3.1 base score is 5.5, reflecting medium severity, with attack vector being network, low attack complexity, high privileges required, no user interaction, and a scope change due to potential impact on other components. No public exploits or active exploitation have been reported so far. The vulnerability was published on February 17, 2025, and no official patches or fixes are linked yet, indicating the need for immediate attention from site administrators.

The primary impact of this SSRF vulnerability is the potential for attackers with administrator access to leverage the Stream plugin's webhook feature to perform unauthorized internal network reconnaissance and interact with internal services that are otherwise inaccessible externally. This can lead to information disclosure, such as accessing sensitive internal endpoints, metadata services, or configuration data. Additionally, if internal services accept modification requests, attackers could alter data or configurations, potentially leading to integrity violations. While the vulnerability does not directly affect availability, it can facilitate lateral movement within the network or serve as a stepping stone for further attacks. Organizations running WordPress sites with the Stream plugin installed and having sensitive internal services accessible from the web server are at risk. The requirement for administrator-level access limits the threat to compromised or malicious insiders, but the consequences can be significant, especially in environments with critical internal services. The vulnerability could also be exploited in multi-tenant hosting environments to attack other tenants' internal services. Overall, the impact includes confidentiality and integrity risks to internal systems and data, with potential for broader network compromise if combined with other vulnerabilities or misconfigurations.

To mitigate CVE-2024-13879, organizations should first verify if the Stream plugin is installed and identify the version in use. Immediate mitigation includes restricting administrator access to trusted personnel only and monitoring for suspicious administrator activity. Since no official patch is currently linked, administrators should consider disabling the webhook feature in the Stream plugin until a fix is available. Implement network segmentation and firewall rules to limit the web server's ability to access sensitive internal services, reducing the impact of SSRF exploitation. Employ web application firewalls (WAFs) with custom rules to detect and block unusual outbound requests originating from the WordPress server. Regularly audit and rotate administrator credentials and enable multi-factor authentication to reduce the risk of compromised admin accounts. Monitor logs for unusual internal requests or webhook activity. Once a patch is released, apply it promptly. Additionally, consider deploying runtime application self-protection (RASP) solutions that can detect and block SSRF attempts in real time. Finally, conduct internal penetration testing focusing on SSRF vectors to identify and remediate similar issues proactively.