CVE-2025-49425 is a high-severity vulnerability classified as CWE-352, indicating a Cross-Site Request Forgery (CSRF) issue in the Adrian Hanft Konami Easter Egg product, affecting versions up to v0.4. The vulnerability allows an attacker to perform unauthorized actions on behalf of an authenticated user by exploiting the lack of proper CSRF protections. This CSRF flaw leads to a Stored Cross-Site Scripting (XSS) condition, where malicious scripts injected by the attacker are persistently stored and executed in the context of the victim's browser. The CVSS 3.1 score of 7.1 reflects a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact includes low confidentiality, integrity, and availability losses, but the chained effect of CSRF enabling Stored XSS significantly raises the risk profile. The absence of patches at the time of publication increases exposure. The vulnerability is particularly dangerous because CSRF attacks can be executed via social engineering, tricking users into performing unintended actions, while Stored XSS can lead to session hijacking, credential theft, or further exploitation within the affected web application. The product, Konami Easter Egg, appears to be a niche or specialized software component, but the exact usage context is not detailed. No known exploits in the wild have been reported yet, but the vulnerability's characteristics make it a candidate for exploitation once weaponized.

For European organizations, the impact depends largely on the deployment and usage of the Konami Easter Egg product. If used in internal or customer-facing web applications, the CSRF vulnerability combined with Stored XSS can lead to unauthorized actions being performed without user consent, data leakage, and potential compromise of user accounts or sensitive information. This can result in reputational damage, regulatory non-compliance (e.g., GDPR violations due to data breaches), and operational disruptions. Attackers could leverage this vulnerability to escalate privileges or pivot within networks, especially if the affected applications are integrated with critical business processes. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger the exploit, increasing risk in environments with less user security awareness. The chained nature of CSRF leading to Stored XSS amplifies the threat, as it enables persistent malicious code execution, which can be difficult to detect and remediate. European organizations with web applications incorporating this product or similar vulnerable components should consider this a significant security concern.

1. Immediate mitigation should focus on implementing robust CSRF protections, such as synchronizer tokens (CSRF tokens) or SameSite cookie attributes, to prevent unauthorized request forgery. 2. Conduct a thorough code review of the Konami Easter Egg integration to identify and sanitize all user inputs to prevent Stored XSS, employing context-aware output encoding and input validation. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 4. Educate users about phishing and social engineering risks to reduce the likelihood of successful user interaction exploitation. 5. Monitor web application logs for unusual or suspicious requests that may indicate exploitation attempts. 6. Since no patches are currently available, consider isolating or disabling the vulnerable component until a vendor fix is released. 7. Implement web application firewalls (WAF) with rules targeting CSRF and XSS attack patterns as an additional protective layer. 8. Plan for rapid deployment of vendor patches once available and maintain an incident response plan to address potential exploitation.