ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch) The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters: // lib/dispatcher/client-h1.js:1121 if (upgrade) { header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n` }

A flaw was found in undici, a Node.js HTTP/1.1 client. This vulnerability allows a remote attacker to inject malicious data into HTTP headers or prematurely end HTTP requests by sending specially crafted input to the `upgrade` option of `client.request()`. This is possible because undici does not properly validate input for invalid header characters, which could lead to unauthorized information disclosure or bypassing of security controls.

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch) The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters: // lib/dispatcher/client-h1.js:1121 if (upgrade) { header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n` }

ImpactWhen an application passes user-controlled input to theupgradeop ...

Undici has CRLF Injection in undici via `upgrade` option