CVE-2024-23877 is a high-severity Cross-Site Scripting (XSS) vulnerability identified in version 1.0 of the Cups Easy (Purchase & Inventory) software. The vulnerability arises due to improper neutralization of user-controlled input in the currencyid parameter of the /cupseasylive/currencycreate.php endpoint. Specifically, the application fails to sufficiently encode or sanitize this input before reflecting it in the web page output, allowing an attacker to inject malicious scripts. Exploitation requires the attacker to craft a specially designed URL containing malicious JavaScript code embedded in the currencyid parameter and trick an authenticated user into visiting this URL. Upon execution, the injected script can steal session cookies, potentially leading to session hijacking and unauthorized access to the victim’s account. The CVSS v3.1 base score is 8.2, indicating a high severity level. The vector string (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N) shows that the attack is network exploitable without privileges, requires user interaction (clicking the malicious link), and impacts confidentiality severely by allowing cookie theft, with limited impact on integrity and no impact on availability. The vulnerability affects only version 1.0 of Cups Easy (Purchase & Inventory), and no patches or known exploits in the wild have been reported yet. The CWE classification is CWE-79, which corresponds to improper neutralization of input during web page generation, a common cause of XSS vulnerabilities. This vulnerability could be leveraged in targeted phishing campaigns against users of the affected software, potentially leading to unauthorized access and data exposure within organizations using this product.

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 managed through the software. Successful exploitation could allow attackers to hijack authenticated sessions, leading to unauthorized actions such as viewing or modifying purchase and inventory records. This could disrupt business operations, cause financial losses, and damage trust in the organization’s data integrity. Given that the vulnerability requires user interaction, phishing or social engineering campaigns could be used to target employees, increasing the risk of compromise. The cross-site scripting flaw does not directly affect system availability but could facilitate further attacks if combined with other vulnerabilities or insider threats. Organizations handling sensitive procurement or inventory data must consider the risk of data leakage and unauthorized access, which could have regulatory compliance implications under GDPR if personal or sensitive data is involved. Additionally, the scope of impact is limited to users of the vulnerable software, but given the critical nature of purchase and inventory systems, the operational impact could be substantial.

1. Immediate mitigation should focus on restricting access to the vulnerable endpoint (/cupseasylive/currencycreate.php) through network-level controls such as web application firewalls (WAFs) configured to detect and block malicious input patterns targeting the currencyid parameter. 2. Implement strict input validation and output encoding on the server side to neutralize any user-supplied data before rendering it in the web interface. This includes using context-appropriate encoding (e.g., HTML entity encoding) to prevent script injection. 3. Educate users about the risks of clicking unsolicited or suspicious links, especially those that require authentication to the Cups Easy system. 4. Monitor logs for unusual access patterns or repeated attempts to exploit the currencyid parameter. 5. If possible, upgrade to a patched version once available from the vendor or apply custom patches to sanitize inputs. 6. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts within the application context. 7. Conduct regular security assessments and penetration testing focused on web application vulnerabilities to detect similar issues proactively.