CVE-2025-60246 identifies a reflected Cross-Site Scripting (XSS) vulnerability in the weissmike Simple Finance Calculator, 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 attackers to inject malicious JavaScript code into the application’s responses. When a victim interacts with a crafted URL or input, the malicious script executes in the context of the victim’s browser, potentially leading to session hijacking, data theft, or manipulation of displayed information. The vulnerability has a CVSS v3.1 base score of 7.1, indicating high severity, with an attack vector of network (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 components beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is partial (C:L/I:L/A:L). No known exploits have been reported in the wild yet, but the ease of exploitation and common use cases of the affected product increase the risk. The Simple Finance Calculator is typically used in financial contexts for calculations, making it a valuable target for attackers seeking to manipulate financial data or steal sensitive information. The lack of available patches at the time of publication necessitates immediate mitigation through alternative controls.

For European organizations, the reflected XSS vulnerability in the Simple Finance Calculator can lead to several adverse outcomes. Attackers can exploit this flaw to execute arbitrary scripts in users’ browsers, potentially stealing authentication tokens, personal data, or financial information. This can result in unauthorized access to internal systems or financial fraud. The integrity of financial calculations may be compromised, leading to erroneous financial decisions or reporting. Availability impacts may arise if attackers use the vulnerability to inject scripts that disrupt normal application functionality or launch further attacks. Given the widespread use of financial tools in sectors such as banking, accounting, and corporate finance across Europe, the vulnerability poses a significant risk. Additionally, regulatory frameworks like GDPR impose strict data protection requirements, and exploitation could lead to compliance violations and reputational damage. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger exploitation, increasing the threat surface.

Organizations should prioritize the following specific mitigation steps: 1) Monitor the vendor’s channels for official patches and apply them immediately once available. 2) Implement strict input validation on all user-supplied data to ensure that potentially malicious characters are sanitized or rejected before processing. 3) Employ robust output encoding techniques (e.g., HTML entity encoding) when reflecting user input in web pages to prevent script execution. 4) Deploy Content Security Policies (CSP) to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 5) Educate users about the risks of clicking on suspicious links or inputs, especially in financial applications. 6) Use web application firewalls (WAFs) with updated signatures to detect and block attempted XSS payloads targeting this vulnerability. 7) Conduct regular security assessments and penetration testing focusing on input handling in web applications. 8) Where possible, isolate the finance calculator application within segmented network zones to limit lateral movement in case of compromise.