CyberRota Analysis
AI-GeneratedThe built-in CORS middleware in Hono versions prior to 4.12.34 is vulnerable to a regular expression denial of service (ReDoS) attack, which can lead to significant CPU consumption and potential service unresponsiveness during preflight OPTIONS requests. This vulnerability primarily affects applications using the default configuration of the middleware, particularly those that do not set a non-empty allowHeaders. Developers and system administrators utilizing Hono in environments with shared execution threads should prioritize upgrading to version 4.12.34 to mitigate this risk.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.34, the built-in CORS middleware, hono/cors, is vulnerable to a regular expression denial of service (ReDoS). During a preflight OPTIONS request, the middleware parses the attacker-controlled Access-Control-Request-Headers header using a whitespace-tolerant regular expression whose backtracking makes its running time quadratic in the input length. Because the header value is bounded only by the deployment's maximum HTTP header size, a single preflight carrying a long run of whitespace can consume seconds of CPU and block request processing. On runtimes that share one execution thread across requests, this stalls concurrent requests as well, and repeated requests can render the service unresponsive. This affects the default configuration, since the vulnerable path is reached whenever cors() is used with an unset or empty allowHeaders. Applications that set a non-empty allowHeaders are not affected. This issue is fixed in version 4.12.34.