CVE-2025-43837 is a high-severity reflected Cross-site Scripting (XSS) vulnerability identified in the binti76 Total Donations software, affecting versions up to 3.0.8. This vulnerability arises from improper neutralization of user-supplied input during web page generation, classified under CWE-79. Specifically, the application fails to adequately sanitize or encode input parameters before including them in dynamically generated web pages, allowing an attacker to inject malicious scripts that execute in the context of a victim's browser. The vulnerability is exploitable remotely over the network without requiring authentication (AV:N/AC:L/PR:N), but it does require user interaction (UI:R), such as clicking a crafted link or visiting a malicious webpage. The scope is classified as changed (S:C), indicating that the vulnerability can affect resources beyond the vulnerable component, potentially impacting the confidentiality, integrity, and availability of the application and its users. The CVSS v3.1 base score is 7.1, reflecting a high severity due to the combination of remote exploitability, low attack complexity, and significant impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the presence of this vulnerability in a donation management system could allow attackers to steal session cookies, perform actions on behalf of users, or redirect users to malicious sites, thereby undermining trust and potentially causing financial or reputational damage. The lack of available patches at the time of publication increases the urgency for mitigation.

For European organizations using binti76 Total Donations, this vulnerability poses a significant risk, especially for non-profits, charities, and fundraising platforms that rely on this software to manage donor interactions. Exploitation could lead to unauthorized disclosure of sensitive donor information, manipulation of donation data, or redirection of users to phishing or malware sites. This can result in loss of donor trust, financial fraud, and regulatory non-compliance, particularly under the GDPR framework which mandates protection of personal data. The reflected XSS attack vector could also be leveraged to conduct broader phishing campaigns targeting European users, amplifying the impact. Additionally, the potential for session hijacking or defacement could disrupt service availability and damage organizational reputation. Given the cross-border nature of many European charities and the interconnectedness of donation platforms, the impact could cascade across multiple countries.

European organizations should immediately implement input validation and output encoding controls to neutralize malicious scripts. Specifically, they should: 1) Employ context-aware output encoding (e.g., HTML entity encoding) for all user-supplied data rendered in web pages. 2) Use Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 3) Implement web application firewalls (WAFs) with rules targeting common XSS attack patterns to provide an additional layer of defense. 4) Conduct thorough code reviews and penetration testing focusing on input handling in the Total Donations software. 5) Monitor web traffic for suspicious activity indicative of attempted XSS exploitation. 6) Engage with the vendor or community to obtain patches or updates as soon as they become available. 7) Educate users and administrators about the risks of clicking untrusted links and the importance of reporting suspicious behavior. These steps go beyond generic advice by focusing on layered defenses and proactive monitoring tailored to the specific software and threat.