CVE-2024-41990 is a denial-of-service (DoS) vulnerability identified in the Django web framework, specifically affecting versions before 5.0.8 and 4.2 before 4.2.15. The vulnerability resides in the urlize() and urlizetrunc() template filters, which are used to convert plain text URLs into clickable links within Django templates. The flaw arises when these filters process very large input strings containing a particular sequence of characters, which leads to excessive CPU and memory consumption. This resource exhaustion can cause the Django application to become unresponsive or crash, resulting in a denial of service. The vulnerability is classified under CWE-130, indicating improper handling of input leading to resource exhaustion. The CVSS v3.1 base score is 7.5, reflecting a high severity due to its network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but high impact on availability (A:H). No known exploits have been reported in the wild yet, but the ease of exploitation and the potential impact make it a critical issue for Django-based web applications. The vulnerability can be exploited remotely by an unauthenticated attacker simply by submitting crafted input to the affected filters, making it a significant risk for publicly accessible web services.

For European organizations, the primary impact of CVE-2024-41990 is the potential for denial-of-service attacks against web applications built on vulnerable Django versions. This can lead to service outages, degraded user experience, and potential loss of business continuity. Organizations providing critical online services, e-commerce platforms, or public-facing portals using Django could face operational disruptions. The unavailability of services may also damage reputation and customer trust. Since the vulnerability does not affect confidentiality or integrity, data breaches are unlikely; however, the loss of availability can indirectly affect compliance with service-level agreements (SLAs) and regulatory requirements related to uptime and reliability. The ease of exploitation without authentication increases the threat landscape, making it easier for attackers to disrupt services at scale. European sectors with high reliance on web applications, such as finance, government, healthcare, and technology, are particularly at risk.

The most effective mitigation is to upgrade Django installations to version 5.0.8 or later, or 4.2.15 or later, where the vulnerability has been patched. Until patching is possible, organizations should implement input validation and size restrictions on user inputs processed by urlize() and urlizetrunc() filters to prevent excessively large payloads from being processed. Web application firewalls (WAFs) can be configured to detect and block suspiciously large or malformed inputs targeting these filters. Monitoring application performance and logs for unusual spikes in resource usage can help detect attempted exploitation. Additionally, consider isolating or rate-limiting access to endpoints that utilize these filters to reduce exposure. Security teams should also review template usage to minimize reliance on vulnerable filters or replace them with safer alternatives if feasible. Regular vulnerability scanning and timely application of security updates remain critical to prevent exploitation.