CVE-2024-42749 is a Cross Site Scripting (XSS) vulnerability identified in Alto CMS version 1.1.13. XSS vulnerabilities, classified under CWE-79, occur when an application does not properly sanitize user-supplied input, allowing attackers to inject malicious scripts into web pages viewed by other users. In this case, a local attacker can craft a malicious script that, when executed in the context of the vulnerable CMS, can lead to arbitrary code execution within the victim's browser. This can result in theft of sensitive information such as cookies, session tokens, or other credentials, and potentially enable further attacks like session hijacking or phishing. The CVSS vector indicates the attack can be performed remotely over the network (AV:N), requires low attack complexity (AC:L), no privileges (PR:N), but requires user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality and integrity at a low level (C:L, I:L) but does not affect availability (A:N). No patches or known exploits are currently available, indicating the vulnerability is newly disclosed and not yet actively exploited. The vulnerability's presence in Alto CMS, a content management system, means that websites using this platform could be targeted to compromise user data or site integrity.

For European organizations, the impact of CVE-2024-42749 depends on the extent of Alto CMS deployment. Organizations running Alto CMS 1.1.13 are at risk of attackers exploiting this XSS vulnerability to execute malicious scripts in users' browsers, potentially leading to data leakage, session hijacking, or defacement of websites. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches if personal data is exposed), and cause financial losses. Since the vulnerability requires user interaction, phishing or social engineering campaigns could be used to trigger exploitation. The medium severity suggests a moderate risk but one that should not be ignored, especially for sectors handling sensitive data such as finance, healthcare, or government services. The lack of a patch increases the urgency for temporary mitigations. European organizations with public-facing Alto CMS sites are particularly vulnerable to external attackers aiming to compromise site visitors or administrators.

1. Implement strict input validation and output encoding on all user-supplied data within Alto CMS to prevent injection of malicious scripts. 2. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 3. Educate users and administrators to recognize and avoid interacting with suspicious links or content that could trigger the XSS exploit. 4. Monitor web traffic and logs for unusual activity indicative of attempted XSS exploitation. 5. If possible, isolate Alto CMS instances behind web application firewalls (WAFs) configured to detect and block XSS payloads. 6. Regularly review and update CMS components and plugins to minimize attack surface. 7. Engage with Alto CMS developers or community to track patch releases and apply updates promptly once available. 8. Consider temporary disabling or restricting features that accept user input until a patch is released. 9. Conduct security testing and code review focused on input handling to identify and remediate similar vulnerabilities proactively.