CVE-2025-51971 is a reflected Cross-Site Scripting (XSS) vulnerability identified in the register.php script of the PuneethReddyHC Online Shopping System Advanced 1.0. The vulnerability arises because the application fails to properly sanitize or encode user input submitted via the 'f_name' parameter. This unsanitized input is directly reflected in the server's HTTP response, allowing an attacker to inject arbitrary JavaScript code. When a victim accesses a crafted URL containing malicious script code in the 'f_name' parameter, the injected script executes in the victim's browser context. This can lead to session hijacking, credential theft, defacement, or redirection to malicious sites. Since this is a reflected XSS, exploitation requires the victim to be tricked into clicking a malicious link or visiting a crafted webpage. The vulnerability does not require authentication, making it accessible to unauthenticated remote attackers. No patch or fix has been provided yet, and no known exploits have been reported in the wild. The lack of a CVSS score indicates this is a newly published vulnerability with limited public information. Reflected XSS vulnerabilities are common in web applications that do not implement proper input validation, output encoding, or Content Security Policy (CSP) headers. The affected product is a niche online shopping system, which may limit the scope of impact but still poses a risk to users of that platform.

For European organizations using the PuneethReddyHC Online Shopping System Advanced 1.0, this vulnerability could lead to significant security risks. Attackers could exploit the reflected XSS to steal user session cookies, enabling account takeover or unauthorized transactions. This could result in financial loss, reputational damage, and regulatory non-compliance under GDPR due to inadequate protection of personal data. Additionally, attackers could use the vulnerability to deliver malware or phishing payloads to customers, further amplifying the impact. E-commerce platforms are high-value targets in Europe, and any compromise could erode consumer trust. Even organizations not directly using this software could be affected if their customers or partners use the vulnerable system, potentially creating a supply chain risk. The lack of authentication requirement and ease of exploitation increase the threat level. However, the impact is somewhat limited by the apparent niche usage of the affected software. Nonetheless, any European entity relying on this system should consider the risk significant due to the sensitive nature of online shopping transactions and personal data involved.

To mitigate this vulnerability, organizations should immediately implement proper input validation and output encoding on the 'f_name' parameter in register.php. Specifically, all user-supplied input should be sanitized to remove or encode HTML special characters before reflecting them in HTTP responses. Employing context-aware output encoding libraries or frameworks is recommended. Additionally, implementing a robust Content Security Policy (CSP) can help restrict the execution of unauthorized scripts. Organizations should also conduct thorough security testing, including automated and manual XSS testing, across all input vectors. If a patch from the vendor becomes available, it should be applied promptly. In the interim, web application firewalls (WAFs) can be configured to detect and block typical XSS attack patterns targeting this parameter. User education to avoid clicking suspicious links and monitoring web logs for unusual input patterns can further reduce risk. Finally, organizations should review their incident response plans to quickly address any exploitation attempts.