CVE-2022-31005 is an integer overflow vulnerability affecting the Vapor web framework for Swift, specifically versions prior to 4.60.3 when FileMiddleware is enabled. Vapor is a popular HTTP web framework used to build server-side Swift applications. The vulnerability arises from improper handling of integer values within the FileMiddleware component, which is responsible for serving static files. An integer overflow or wraparound occurs when an arithmetic operation attempts to create a numeric value that is outside the range that can be represented with a given number of bits, causing the value to wrap around to an unexpected number. In this case, the overflow can lead to a crash of the application, resulting in a denial of service (DoS). The vulnerability does not appear to allow for remote code execution or data leakage directly, but the crash can disrupt service availability. The issue was patched in Vapor version 4.60.3. As a temporary workaround, users can disable FileMiddleware and serve static content through an external Content Delivery Network (CDN) to mitigate the risk until the patch is applied. There are no known exploits in the wild at the time of reporting, and the vulnerability is classified under CWE-190 (Integer Overflow or Wraparound). The vulnerability requires the FileMiddleware component to be enabled and does not require authentication or user interaction to be triggered, making it potentially exploitable by unauthenticated remote attackers via crafted HTTP requests targeting static file serving functionality.

For European organizations using the Vapor framework in their web applications, this vulnerability primarily threatens the availability of affected services. A successful exploitation could cause the web server to crash, resulting in downtime and disruption of business operations. This is particularly impactful for organizations relying on Vapor for customer-facing websites, APIs, or internal tools where uptime is critical. While the vulnerability does not directly compromise confidentiality or integrity, the denial of service could indirectly affect business continuity and user trust. Organizations in sectors such as finance, e-commerce, healthcare, and government that depend on Swift-based backend services may experience operational interruptions. Additionally, the need to disable FileMiddleware as a workaround could complicate static content delivery, potentially impacting performance or requiring infrastructure changes. Given that no known exploits exist in the wild, the immediate risk is moderate, but unpatched systems remain vulnerable to potential future attacks.

1. Upgrade to Vapor version 4.60.3 or later as soon as possible to apply the official patch that addresses the integer overflow vulnerability. 2. If immediate upgrading is not feasible, disable FileMiddleware to prevent the vulnerable code path from being executed. 3. Serve static files via a trusted Content Delivery Network (CDN) or alternative static file server to maintain service availability without relying on the vulnerable middleware. 4. Implement robust monitoring and alerting on application crashes and unusual HTTP request patterns targeting static file endpoints to detect potential exploitation attempts early. 5. Conduct thorough testing of the application after applying patches or configuration changes to ensure stability and performance are maintained. 6. Review and limit exposure of the vulnerable endpoints by applying network-level controls such as web application firewalls (WAFs) that can filter malformed requests targeting static file serving. 7. Educate development and operations teams about the risks of integer overflow vulnerabilities and encourage secure coding practices to prevent similar issues in custom middleware or extensions.