CVE-2025-60246 is a reflected Cross-site Scripting (XSS) vulnerability found in the weissmike Simple Finance Calculator, affecting versions up to and including 1.0. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows an attacker to inject malicious JavaScript code that is reflected back to the victim's browser. When a user interacts with a crafted URL or input, the malicious script executes in the context of the vulnerable web application, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The CVSS 3.1 base score of 7.1 reflects a high severity due to the 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), indicating that the vulnerability affects resources beyond the vulnerable component, and it impacts confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L). No patches or known exploits are currently available, but the vulnerability is publicly disclosed and should be addressed promptly. The Simple Finance Calculator is a web-based tool likely used by financial professionals or consumers for financial calculations, making it a valuable target for attackers aiming to steal sensitive financial data or credentials.

For European organizations, especially those in financial services, banking, and consultancy sectors that may use the weissmike Simple Finance Calculator, this vulnerability poses a significant risk. Successful exploitation can lead to unauthorized access to user sessions, theft of sensitive financial data, and potential manipulation of financial calculations or reports. This can result in financial loss, reputational damage, regulatory penalties under GDPR, and erosion of customer trust. The reflected XSS nature means phishing campaigns could be used to lure users into clicking malicious links, amplifying the attack's reach. Additionally, the vulnerability could serve as a foothold for further attacks within corporate networks if exploited in internal deployments. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often weaponize disclosed vulnerabilities rapidly.

Specific mitigation steps include: 1) Immediate review and update of the Simple Finance Calculator to a patched version once available from weissmike; 2) In the absence of a patch, implement strict input validation and sanitization on all user-supplied data to neutralize potentially malicious scripts; 3) Employ robust output encoding (e.g., HTML entity encoding) when reflecting user input in web pages; 4) Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts; 5) Educate users to recognize and avoid clicking suspicious links, especially those purporting to be from trusted financial tools; 6) Monitor web application logs for unusual input patterns indicative of attempted XSS exploitation; 7) Consider using web application firewalls (WAFs) with rules designed to detect and block reflected XSS attacks targeting this application; 8) For organizations hosting the calculator internally, restrict access to trusted users and networks to reduce exposure.