Overview
About vulnerability
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
}
Details
- Affected product:
- undici
- Affected packages:
- undici @ 6.11.1 (+2 more)
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
}