CVE-2024-29988 is a high-severity vulnerability affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability is categorized under CWE-693, which relates to Protection Mechanism Failure. Specifically, this issue involves a bypass of the SmartScreen prompt security feature. SmartScreen is a security component in Windows designed to protect users by warning or blocking the execution of unrecognized or potentially malicious applications and files downloaded from the internet. The bypass allows an attacker to circumvent these prompts, potentially enabling the execution of malicious code without the usual user warnings. According to the CVSS 3.1 vector (8.8), the vulnerability can be exploited remotely over the network (AV:N) with low attack complexity (AC:L), requires no privileges (PR:N), but does require user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The exploitability factor is functional (E:F), and the remediation level is official (RL:O) with confirmed report confidence (RC:C). No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability essentially undermines a critical defense layer in Windows 10 1809, allowing attackers to deliver and execute malicious payloads more stealthily by avoiding SmartScreen warnings, increasing the risk of successful phishing, malware infections, and lateral movement within networks.

For European organizations, this vulnerability poses a significant risk, especially for those still operating legacy systems like Windows 10 Version 1809, which despite being an older release, remains in use in various sectors due to compatibility or upgrade delays. The bypass of SmartScreen prompts can lead to increased successful delivery of malware, ransomware, or advanced persistent threats (APTs), potentially compromising sensitive data, disrupting operations, and causing financial and reputational damage. Critical infrastructure, government agencies, healthcare, finance, and manufacturing sectors are particularly vulnerable due to their reliance on Windows environments and the high value of their data. The high impact on confidentiality, integrity, and availability means that attacks exploiting this vulnerability could result in data breaches, unauthorized system control, and service outages. The requirement for user interaction means social engineering or phishing campaigns could be leveraged to trigger exploitation, which is a common attack vector in Europe. The absence of known exploits in the wild currently provides a window for mitigation, but the functional exploitability suggests attackers may develop weaponized exploits soon.

1. Immediate prioritization of upgrading affected systems from Windows 10 Version 1809 to a supported and patched Windows version is critical, as no patches are currently linked for this vulnerability. 2. Implement application whitelisting and restrict execution of untrusted or unsigned applications to reduce reliance on SmartScreen as a sole defense. 3. Enhance user awareness training focusing on phishing and social engineering tactics, emphasizing caution when interacting with unexpected prompts or downloads. 4. Deploy endpoint detection and response (EDR) solutions capable of detecting anomalous behaviors indicative of exploitation attempts bypassing SmartScreen. 5. Utilize network segmentation to limit lateral movement if an endpoint is compromised. 6. Monitor network traffic and logs for unusual activities, especially those involving execution of new or unrecognized binaries. 7. Employ multi-factor authentication (MFA) and least privilege principles to reduce the impact of potential breaches. 8. Regularly review and update security policies to incorporate compensating controls until official patches are released.