CVE-2024-11831 is a Cross-site Scripting (XSS) vulnerability identified in the npm package serialize-javascript, specifically version 6.0. The vulnerability stems from improper neutralization of input during web page generation, where the serialize-javascript module fails to adequately sanitize certain input types, including regular expressions and other JavaScript object types. This improper sanitization allows an attacker to inject malicious JavaScript code into serialized data. When this data is deserialized and rendered in a web browser, the injected code executes within the context of the vulnerable web application, leading to XSS attacks. Such attacks can compromise user sessions, steal sensitive information, or manipulate the web application's behavior. The vulnerability is particularly critical in environments where serialized data is transmitted to web clients, as it directly impacts the security of websites or web applications relying on this package. The CVSS 3.1 base score is 5.4 (medium severity), with an attack vector of network (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), and user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability affects resources beyond the initially vulnerable component. Confidentiality and integrity impacts are low, with no impact on availability. No known exploits are currently reported in the wild, but the vulnerability is publicly disclosed and should be addressed promptly. The lack of a vendor project or product name suggests this vulnerability is tied to the npm package ecosystem, widely used in JavaScript and Node.js web applications.

For European organizations, the impact of CVE-2024-11831 can be significant, especially for those relying on Node.js and npm packages in their web application stacks. Successful exploitation could lead to the execution of arbitrary JavaScript in users' browsers, enabling session hijacking, credential theft, or unauthorized actions performed on behalf of users. This can damage organizational reputation, lead to data breaches, and cause regulatory compliance issues under GDPR due to the exposure of personal data. The vulnerability's medium severity reflects moderate risk, but the changed scope means that the impact could extend beyond the immediate application, potentially affecting integrated systems or services. Organizations operating customer-facing web applications or internal portals that serialize data for client-side consumption are particularly at risk. The requirement for some privileges and user interaction reduces the likelihood of automated widespread exploitation but does not eliminate targeted attacks. Given the widespread use of serialize-javascript in European software development, the vulnerability could affect a broad range of sectors including finance, healthcare, government, and e-commerce.

European organizations should take the following specific mitigation steps: 1) Immediately upgrade serialize-javascript to a patched version once available or apply vendor-provided patches. 2) Implement strict input validation and sanitization on all data before serialization, especially for complex JavaScript objects like regex. 3) Adopt Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4) Conduct thorough code reviews and static analysis focusing on serialization and deserialization logic to identify unsafe patterns. 5) Use security-focused libraries or frameworks that handle serialization securely by default. 6) Monitor web application logs and user reports for signs of XSS exploitation attempts. 7) Educate developers on secure coding practices related to serialization and deserialization. 8) Employ runtime application self-protection (RASP) or web application firewalls (WAF) configured to detect and block XSS payloads. 9) Limit privileges of application components that handle serialization to reduce the impact of potential exploitation. 10) Test web applications regularly with automated and manual penetration testing focused on XSS vectors involving serialized data.