CVE-2023-38180 is a denial of service vulnerability identified in Microsoft ASP.NET Core 2.1, specifically affecting version 2.0. The vulnerability is classified under CWE-400, which relates to uncontrolled resource consumption leading to service unavailability. An attacker can remotely trigger this vulnerability without requiring any authentication or user interaction, making it relatively easy to exploit over the network. The attack vector is network-based (AV:N), with low attack complexity (AC:L), and no privileges or user interaction needed (PR:N/UI:N). The vulnerability impacts availability (A:H) but does not affect confidentiality or integrity. The CVSS v3.1 base score is 7.5, indicating a high severity level. Although no public exploits have been reported yet, the potential for denial of service attacks against web applications running on ASP.NET Core 2.1 is significant. This version of ASP.NET Core is out of mainstream support, increasing the risk for organizations that have not migrated to newer, supported versions. The vulnerability could allow attackers to exhaust server resources, causing application crashes or unresponsiveness, thereby disrupting business operations dependent on these web services.

For European organizations, the impact of CVE-2023-38180 can be substantial, particularly for those relying on legacy ASP.NET Core 2.1 applications in critical infrastructure, government services, finance, healthcare, and e-commerce sectors. A successful denial of service attack could lead to prolonged downtime, affecting service availability and potentially causing financial losses, reputational damage, and regulatory compliance issues under GDPR and other data protection laws. The disruption of web services can also impact customer trust and operational continuity. Organizations using outdated ASP.NET Core versions are more vulnerable due to lack of vendor support and patches. The risk is amplified in environments where redundancy and failover mechanisms are insufficient or improperly configured. Given the ease of exploitation and network accessibility, attackers could launch volumetric or targeted DoS attacks, potentially leveraging this vulnerability as part of larger multi-vector campaigns.

To mitigate CVE-2023-38180, European organizations should prioritize upgrading ASP.NET Core applications to the latest supported versions, such as ASP.NET Core 3.1 or later, which receive active security updates. If immediate upgrade is not feasible, organizations should monitor Microsoft’s official channels for any patches or security advisories addressing this vulnerability and apply them promptly. Implementing robust network-level protections such as Web Application Firewalls (WAFs) with rules to detect and block abnormal traffic patterns can help mitigate exploitation attempts. Rate limiting and connection throttling on web servers can reduce the risk of resource exhaustion. Additionally, deploying comprehensive monitoring and alerting for unusual spikes in resource usage or traffic can enable early detection of DoS attempts. Ensuring proper capacity planning and failover strategies will also help maintain service availability during attack attempts. Finally, organizations should conduct security assessments and penetration testing focused on DoS resilience for their ASP.NET Core applications.