CVE-2025-13999 is a Server-Side Request Forgery (SSRF) vulnerability classified under CWE-918, affecting the bplugins HTML5 Audio Player – The Ultimate No-Code Podcast, MP3 & Audio Player WordPress plugin versions 2.4.0 through 2.5.1. The vulnerability resides in the getIcyMetadata() function, which processes metadata for streaming audio content. Due to insufficient validation of user-supplied URLs, an unauthenticated attacker can craft requests that cause the server to perform arbitrary HTTP requests to internal or external systems. This SSRF can be exploited to access internal services that are otherwise inaccessible externally, potentially exposing sensitive information or enabling further attacks such as internal network reconnaissance, data exfiltration, or modification of internal resources. The vulnerability does not require authentication or user interaction, increasing its risk profile. The CVSS v3.1 base score is 7.2, with vector AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N, indicating network attack vector, low attack complexity, no privileges or user interaction required, and a scope change due to impact on resources beyond the vulnerable component. The impact primarily affects confidentiality and integrity, with no direct availability impact. No patches were listed at the time of disclosure, and no known exploits have been observed in the wild. However, the presence of this vulnerability in a popular WordPress plugin used for podcasting and audio playback means that many websites could be exposed, especially those hosting internal services accessible from the web server. Attackers could leverage this SSRF to pivot into internal networks or access cloud metadata services, depending on the hosting environment.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress sites with the affected plugin installed. Organizations hosting internal services such as intranet portals, cloud metadata endpoints, or internal APIs accessible from the web server could have these services queried or manipulated by attackers. This could lead to unauthorized disclosure of sensitive information, including credentials or configuration data, and potentially allow attackers to escalate privileges or move laterally within the network. Media companies, podcast platforms, and content providers using this plugin are particularly at risk, as exploitation could compromise their infrastructure and content integrity. The vulnerability's ease of exploitation without authentication increases the likelihood of automated scanning and attacks. Additionally, the scope change in the CVSS vector indicates that the impact extends beyond the plugin itself, potentially affecting the broader internal network. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers often develop exploits rapidly after disclosure. European data protection regulations such as GDPR also mean that data breaches resulting from this vulnerability could lead to significant legal and financial consequences.

1. Immediate mitigation should focus on network-level controls: restrict outbound HTTP/HTTPS requests from the web server hosting the WordPress plugin to only trusted destinations, using firewall rules or proxy configurations. 2. Monitor and log outbound requests from the web server to detect anomalous or unexpected destinations, which may indicate exploitation attempts. 3. Isolate internal services and metadata endpoints (e.g., cloud provider metadata APIs) to only allow access from authorized systems, preventing SSRF from reaching these targets. 4. Apply strict input validation and sanitization on any user-supplied URLs or parameters related to audio metadata if custom modifications are possible. 5. Regularly check for and apply official patches or updates from the plugin vendor once available. 6. Conduct security assessments and penetration testing focusing on SSRF vectors in WordPress environments. 7. Educate site administrators about the risks of installing plugins from unverified sources and maintaining up-to-date software. 8. Consider disabling or replacing the affected plugin with alternative audio player solutions that do not exhibit SSRF vulnerabilities.