CVE-2024-38156 is a cross-site scripting (XSS) vulnerability classified under CWE-79 affecting Microsoft Edge (Chromium-based). This vulnerability arises from improper neutralization of input during web page generation, allowing an attacker to inject malicious scripts into web content rendered by the browser. The vulnerability is exploitable remotely over the network without requiring any privileges or authentication, but it does require user interaction, such as clicking a crafted link or visiting a malicious webpage. The CVSS 3.1 base score is 6.1 (medium), reflecting the network attack vector, low attack complexity, no privileges required, but user interaction is necessary. The scope is changed (S:C), indicating that exploitation can affect resources beyond the vulnerable component, potentially impacting confidentiality and integrity, but not availability. The vulnerability can be leveraged for spoofing attacks, potentially tricking users into disclosing sensitive information or executing unauthorized actions. No known exploits are currently in the wild, and no official patches have been released yet. The vulnerability was reserved in June 2024 and published in July 2024, indicating recent discovery. Given Edge’s widespread use in enterprise and consumer environments, this vulnerability poses a significant risk if exploited, especially in contexts where users might be targeted with phishing or social engineering campaigns.

For European organizations, the impact of CVE-2024-38156 can be significant due to the widespread use of Microsoft Edge in both corporate and public sectors. Successful exploitation could lead to partial compromise of confidentiality and integrity by enabling attackers to execute arbitrary scripts in the context of trusted websites, potentially stealing session tokens, credentials, or other sensitive data. This can facilitate further attacks such as account takeover, data exfiltration, or lateral movement within networks. The vulnerability does not affect availability directly but can undermine trust in web applications and internal portals. Sectors such as finance, government, healthcare, and critical infrastructure are particularly at risk due to the sensitivity of data handled and the potential for targeted spear-phishing attacks leveraging this vulnerability. The requirement for user interaction means that social engineering remains a key attack vector, emphasizing the need for user training and awareness. The lack of a current patch increases the window of exposure, making proactive mitigations critical.

1. Monitor for official Microsoft Edge security updates and apply patches immediately once available to remediate the vulnerability. 2. Implement strict Content Security Policies (CSP) on web applications to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 3. Employ browser security features such as Enhanced Protected Mode and site isolation where applicable to limit script execution scope. 4. Educate users about the risks of clicking on suspicious links or visiting untrusted websites, emphasizing caution with unsolicited emails or messages. 5. Use endpoint protection solutions that can detect and block malicious scripts or suspicious browser behavior. 6. Conduct regular security assessments and penetration testing focusing on web application security to identify and remediate similar vulnerabilities. 7. Consider deploying web filtering and URL reputation services to block access to known malicious sites. 8. For organizations with custom web applications, review and harden input validation and output encoding practices to prevent injection of malicious content that could be exploited via the browser.