CVE-2025-15414 is a server-side request forgery vulnerability affecting the go-sonic sonic software versions 1.1.0 to 1.1.4. The vulnerability resides in the FetchTheme function within the Theme Fetching API, specifically in the git_fetcher.go source file. This function accepts a URI parameter that is not properly validated or sanitized, allowing an attacker to manipulate it to cause the server to initiate unauthorized HTTP requests to arbitrary destinations. SSRF vulnerabilities can be leveraged to access internal services that are otherwise inaccessible externally, potentially exposing sensitive data or enabling further attacks such as port scanning or exploitation of internal vulnerabilities. The vulnerability can be exploited remotely without requiring authentication or user interaction, increasing its risk profile. The vendor was notified early but has not issued a patch or response, and no public exploits have been observed in the wild yet. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges or user interaction required, and limited impact on confidentiality, integrity, and availability, resulting in a medium severity score of 5.1. This vulnerability is particularly concerning for environments where go-sonic sonic is used in network segments with access to sensitive internal resources. Without proper mitigations, attackers could leverage this flaw to pivot within internal networks or exfiltrate data by abusing the server's network capabilities.

For European organizations, the SSRF vulnerability in go-sonic sonic could lead to unauthorized internal network reconnaissance, exposure of sensitive internal services, and potential data leakage. Organizations using this software in critical infrastructure, development environments, or internal tooling may face increased risk of lateral movement by attackers. The ability to exploit the vulnerability remotely without authentication means attackers can target exposed instances from outside the network perimeter. This could undermine confidentiality by exposing internal endpoints, integrity if attackers leverage SSRF to interact with internal APIs, and availability if internal resources are overwhelmed or manipulated. The lack of vendor response and patch availability increases the window of exposure. Industries such as finance, healthcare, and government in Europe, which often have strict data protection requirements, may experience compliance risks if internal data is exposed. Additionally, SSRF can be a stepping stone for more complex attacks, increasing overall organizational risk.

1. Implement strict input validation and sanitization on the URI parameter in the FetchTheme function to ensure only trusted and expected URIs are processed. 2. Employ network segmentation and firewall rules to restrict the server’s outbound HTTP requests to only necessary and trusted destinations, preventing arbitrary external or internal network access. 3. Monitor and log outbound requests from the go-sonic sonic server to detect anomalous or unexpected connections indicative of exploitation attempts. 4. If possible, disable or restrict the Theme Fetching API functionality until a vendor patch or official fix is available. 5. Use web application firewalls (WAFs) or intrusion detection systems (IDS) with rules tailored to detect SSRF patterns targeting this component. 6. Conduct internal audits to identify all instances of go-sonic sonic and assess exposure levels, prioritizing remediation in high-risk environments. 7. Engage in vulnerability management processes to track updates from the vendor or community for patches or mitigations. 8. Consider deploying network-level proxies or request filtering to control and validate outgoing requests from the application server.