CVE-2024-23855 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-controlled input during web page generation, specifically in the /cupseasylive/taxcodemodify.php endpoint. Multiple parameters in this endpoint fail to sufficiently encode input, allowing an attacker to inject malicious scripts. Exploitation requires the attacker to craft a specially designed URL containing the malicious payload and trick an authenticated user into accessing it. Upon execution, the injected script can steal the victim's session cookie credentials, potentially enabling session hijacking and unauthorized access to the victim's account. The CVSS v3.1 base score is 8.2, reflecting a network attack vector with low attack complexity, no privileges required, but requiring user interaction. The scope is changed, indicating that the vulnerability affects resources beyond the vulnerable component. Confidentiality impact is high due to session cookie theft, integrity impact is low, and availability is unaffected. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability is assigned CWE-79, which covers improper neutralization of input leading to XSS. This vulnerability is critical for organizations relying on Cups Easy 1.0 for inventory and purchase management, as it can lead to account compromise and unauthorized data access through session hijacking.

For European organizations using Cups Easy (Purchase & Inventory) version 1.0, this vulnerability poses a significant risk to the confidentiality of sensitive business data and user accounts. Successful exploitation can lead to session hijacking, allowing attackers to impersonate legitimate users and potentially manipulate purchase and inventory records. This could disrupt supply chain operations, financial reporting, and inventory management, causing operational and reputational damage. Since the vulnerability requires user interaction and an authenticated session, phishing or social engineering campaigns could be leveraged to exploit it. The lack of available patches increases the window of exposure. Additionally, regulatory frameworks such as GDPR impose strict requirements on protecting personal and business data, and a breach resulting from this vulnerability could lead to compliance violations and financial penalties. The impact is heightened in sectors where inventory and purchase data are critical, such as manufacturing, retail, and logistics companies operating within Europe.

European organizations should immediately assess their use of Cups Easy (Purchase & Inventory) version 1.0 and restrict access to the vulnerable /cupseasylive/taxcodemodify.php endpoint where possible. Implementing Web Application Firewalls (WAFs) with rules to detect and block XSS payloads targeting this endpoint can provide temporary protection. Organizations should enforce strict input validation and output encoding on all user-supplied data within their environment, especially if they have customized or extended the software. User awareness training to recognize phishing attempts that could deliver malicious URLs is critical. Network segmentation and limiting access to the application to trusted internal networks can reduce exposure. Monitoring web server logs for suspicious requests targeting the vulnerable parameters can help detect exploitation attempts. Since no official patch is currently available, organizations should engage with the vendor for timelines and consider applying custom fixes or mitigations, such as disabling the vulnerable functionality if feasible. Finally, enforcing multi-factor authentication (MFA) can reduce the risk of session hijacking leading to full account compromise.