CVE-2024-23860 is a high-severity Cross-Site Scripting (XSS) vulnerability identified in version 1.0 of Cups Easy (Purchase & Inventory), a software product used for purchase and inventory management. The vulnerability arises due to improper neutralization of user-supplied input in the web application, specifically in the 'description' parameter of the /cupseasylive/currencylist.php endpoint. Because the input is not sufficiently encoded or sanitized before being reflected in the web page, an attacker can craft a malicious URL containing executable script code. When an authenticated user accesses this URL, the malicious script executes in their browser context, enabling the attacker to steal session cookies or perform other unauthorized actions on behalf of the user. The vulnerability requires no privileges (PR:N) but does require user interaction (UI:R), as the victim must click or visit the malicious link. The attack vector is network-based (AV:N), meaning exploitation can be attempted remotely over the internet. The vulnerability impacts confidentiality significantly (C:H) by enabling session hijacking, with limited impact on integrity (I:L) and no impact on availability (A:N). The scope is changed (S:C), indicating that exploitation could affect resources beyond the vulnerable component. No public exploits are currently known in the wild, and no patches have been published yet. The vulnerability is tracked by INCIBE and was published on January 26, 2024.

For European organizations using Cups Easy (Purchase & Inventory) version 1.0, this vulnerability poses a significant risk to the confidentiality of user sessions and potentially sensitive business data. Attackers could leverage this XSS flaw to hijack authenticated sessions, leading to unauthorized access to purchase and inventory data, manipulation of records, or further lateral movement within the organization's network. Given that the vulnerability requires user interaction, phishing or social engineering campaigns could be used to trick employees into clicking malicious links. The compromise of session cookies could also facilitate privilege escalation or data exfiltration. This risk is particularly critical for organizations handling sensitive procurement or inventory information, including retail, manufacturing, and logistics sectors prevalent across Europe. Additionally, the vulnerability could undermine trust in internal web applications and lead to regulatory compliance issues under GDPR if personal or sensitive data is exposed or misused.

1. Immediate mitigation should focus on educating users to avoid clicking suspicious or unsolicited links, especially those targeting the currencylist.php endpoint with unusual parameters. 2. Implement Web Application Firewall (WAF) rules to detect and block malicious payloads targeting the 'description' parameter. 3. Apply strict Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of XSS attacks. 4. Conduct a thorough code review and implement proper output encoding and input validation for all user-supplied data, particularly in the affected endpoint. 5. Monitor web server logs for unusual requests or patterns indicative of exploitation attempts. 6. Coordinate with the vendor for an official patch or update and prioritize its deployment once available. 7. Consider isolating or restricting access to the Cups Easy application to trusted networks or VPN users to reduce exposure. 8. Regularly update session management practices, such as using HttpOnly and Secure flags on cookies, to limit cookie theft impact.