CVE-2025-46657 is a high-severity reflected Cross-site Scripting (XSS) vulnerability identified in the Karaz Karazal web application. This vulnerability arises from improper neutralization of user-supplied input during web page generation, specifically via the 'lang' parameter in the default URI. When an attacker crafts a malicious URL containing a specially designed payload in the 'lang' parameter, the application reflects this input back in the HTTP response without adequate sanitization or encoding. This allows the execution of arbitrary JavaScript code in the context of the victim's browser. The vulnerability affects version 0 of Karazal and was published on April 27, 2025. The CVSS 3.1 base score is 7.2, indicating a high severity level. The vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N) reveals that the attack can be performed remotely over the network without any privileges or user interaction, and it impacts confidentiality and integrity with a scope change, but does not affect availability. Although no known exploits are currently reported in the wild, the ease of exploitation and the lack of required authentication make this vulnerability a significant risk. The reflected XSS can be leveraged to steal session cookies, perform actions on behalf of users, or redirect users to malicious sites, potentially leading to account compromise or data leakage. The absence of a patch link suggests that a fix may not yet be available, emphasizing the need for immediate mitigation efforts.

For European organizations using Karaz Karazal, this vulnerability poses a substantial risk to web application security and user data confidentiality. Exploitation could lead to session hijacking, unauthorized actions performed under the victim's credentials, and exposure of sensitive information. This is particularly critical for sectors handling personal data under GDPR regulations, such as finance, healthcare, and government services, where data breaches can result in severe legal and financial consequences. The reflected XSS can also be used as a vector for phishing attacks, undermining user trust and potentially facilitating further malware distribution. The scope change indicated in the CVSS vector means that the vulnerability could affect resources beyond the initially vulnerable component, potentially impacting other integrated systems or services. Given the lack of required user interaction, automated exploitation attempts could increase, raising the likelihood of widespread attacks. The absence of known exploits currently provides a window for proactive defense, but the high ease of exploitation necessitates urgent attention to prevent compromise.

1. Immediate implementation of input validation and output encoding on the 'lang' parameter to neutralize malicious scripts. Use context-aware encoding libraries that properly escape characters based on where the input is reflected (e.g., HTML, JavaScript). 2. Employ a Web Application Firewall (WAF) with custom rules to detect and block suspicious payloads targeting the 'lang' parameter until a vendor patch is available. 3. Conduct thorough code reviews and security testing focusing on all user-controllable inputs, especially those reflected in responses, to identify and remediate similar XSS vectors. 4. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. 5. Educate users and administrators about the risks of reflected XSS and encourage vigilance regarding suspicious URLs or unexpected application behavior. 6. Monitor web server logs for unusual requests containing script tags or encoded payloads in the 'lang' parameter to detect exploitation attempts early. 7. Engage with the vendor to obtain timely patches or updates and prioritize their deployment once available. 8. Where feasible, isolate or limit access to the affected Karazal instances, especially in sensitive environments, until the vulnerability is fully mitigated.