CVE-2024-11695 is a vulnerability identified in Mozilla Firefox and Thunderbird browsers that enables URL bar spoofing via manipulation of punycode and whitespace characters, particularly involving Arabic script. The flaw arises because the browser incorrectly renders certain crafted URLs, allowing an attacker to disguise the true domain name in the address bar. This can mislead users into believing they are visiting a legitimate site when in fact they are on a malicious one, facilitating phishing and social engineering attacks. The vulnerability affects Firefox versions prior to 133 and Thunderbird versions prior to 133 and ESR versions prior to 128.5. The attack vector is remote with no privileges required, but it does require user interaction such as clicking a malicious link. The vulnerability is classified under CWE-1021 (Improper Restriction of Rendered UI Layers or Frames). The CVSS 3.1 base score is 5.4, indicating a medium severity with low complexity to exploit (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The impact primarily affects confidentiality and integrity by enabling spoofing of the URL bar, potentially leading to credential theft or malware delivery. Availability is not impacted. No public exploits have been reported yet, but the vulnerability is published and should be addressed promptly. The lack of patch links suggests fixes may be pending or recently released. This vulnerability highlights the challenges in handling internationalized domain names and complex scripts in browser UI rendering.

For European organizations, this vulnerability poses a significant risk of phishing attacks that can lead to credential compromise, unauthorized access, and potential data breaches. Since Firefox is widely used across Europe, especially in government, education, and enterprise sectors, the ability to spoof URLs can undermine user trust and security awareness efforts. Attackers could craft URLs that appear to originate from trusted domains, increasing the likelihood of successful social engineering campaigns. This is particularly concerning for organizations handling sensitive personal data under GDPR, as phishing-induced breaches could result in regulatory penalties and reputational damage. The vulnerability does not affect system availability but threatens confidentiality and integrity of user interactions. Organizations with remote or hybrid workforces relying on Firefox for web access are especially vulnerable. The absence of known exploits in the wild provides a window for proactive mitigation before widespread attacks occur.

1. Immediately monitor Mozilla’s official channels for patches addressing CVE-2024-11695 and apply updates to Firefox and Thunderbird as soon as they become available, prioritizing versions 133 and above or ESR 128.5 and above. 2. Implement enterprise-wide browser update policies to ensure timely deployment of security patches. 3. Educate users about the risks of clicking suspicious links, especially those with unusual characters or scripts in URLs, emphasizing vigilance with emails and messages containing Arabic script or whitespace anomalies. 4. Deploy email filtering and web gateway solutions capable of detecting and blocking URLs with suspicious punycode or Unicode manipulations. 5. Utilize browser security features such as enhanced phishing protection and URL highlighting to help users identify potentially spoofed URLs. 6. Conduct phishing simulation exercises tailored to this vulnerability to raise awareness. 7. For critical systems, consider restricting browser usage to updated versions or alternative browsers until patches are confirmed. 8. Monitor network traffic for unusual URL patterns indicative of exploitation attempts. 9. Collaborate with incident response teams to prepare for potential phishing campaigns exploiting this vulnerability.