CVE-2025-57407 is a stored cross-site scripting (XSS) vulnerability identified in the Admin Log Viewer component of S-Cart versions up to and including 10.0.3. This vulnerability arises because the application improperly sanitizes or encodes the User-Agent HTTP header before displaying it in the security log page viewed by administrators. An authenticated remote attacker can exploit this by crafting a malicious User-Agent header containing arbitrary JavaScript or HTML code. When an administrator accesses the log viewer page, the injected script executes in their browser context. This stored XSS attack can lead to session hijacking, allowing the attacker to impersonate the administrator, or perform other malicious actions such as privilege escalation, data theft, or further compromise of the administrative interface. The vulnerability requires the attacker to be authenticated, indicating some level of access control is bypassed or misused. The CVSS v3.1 base score is 5.4 (medium severity), reflecting network attack vector, low attack complexity, required privileges, user interaction needed, and partial impact on confidentiality and integrity but no impact on availability. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability is categorized under CWE-79, which corresponds to improper neutralization of input during web page generation leading to XSS.

For European organizations using S-Cart e-commerce platforms, this vulnerability poses a significant risk to administrative security. Successful exploitation could allow attackers to hijack administrator sessions, leading to unauthorized access to sensitive backend functions such as order management, customer data, and system configuration. This could result in data breaches involving personal data protected under GDPR, causing regulatory penalties and reputational damage. The stored nature of the XSS means the malicious payload persists until removed, increasing exposure time. Since the attack requires authentication, insider threats or compromised user accounts could be leveraged to exploit this vulnerability. The partial impact on confidentiality and integrity could facilitate further lateral movement or privilege escalation within the affected environment. Although availability is not impacted, the compromise of administrative control can disrupt business operations and trust in the platform. Given the widespread use of S-Cart in small to medium European online retailers, the threat could affect a broad range of organizations, especially those with less mature security monitoring and patch management processes.

To mitigate this vulnerability, organizations should implement the following specific measures: 1) Apply input validation and output encoding on all HTTP headers, especially User-Agent, before rendering in the admin log viewer to neutralize any embedded scripts. 2) Restrict access to the Admin Log Viewer to only highly trusted administrator accounts and consider multi-factor authentication to reduce risk from compromised credentials. 3) Monitor and audit logs for unusual User-Agent strings or repeated failed authentication attempts that could indicate exploitation attempts. 4) Implement Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of XSS attacks. 5) Regularly update S-Cart installations and monitor vendor advisories for patches addressing this vulnerability. 6) Educate administrators about the risks of clicking on suspicious links or viewing untrusted logs. 7) Consider deploying web application firewalls (WAFs) with custom rules to detect and block malicious User-Agent payloads targeting the log viewer. These targeted mitigations go beyond generic advice by focusing on the specific attack vector and the administrative context of the vulnerability.