GHSA-4992-7rv2-5pvq
Undici has CRLF Injection in undici via `upgrade` option
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
When an application passes user-controlled input to the `upgrade` option of `client.request()`, an attacker can inject CRLF sequences (`\r\n`) to:
1. Inject arbitrary HTTP headers
2. 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:
```javascript
// lib/dispatcher/client-h1.js:1121
if (upgrade) {
header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n`
}
```
### Patches
Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.
### Workarounds
Sanitize the `upgrade` option string before passing to undici:
```javascript
function sanitizeUpgrade(value) {
if (/[\r\n]/.test(value)) {
throw new Error('Invalid upgrade value')
}
return value
}
client.request({
upgrade: sanitizeUpgrade(userInput)
})
```
References
External links from the advisory. They lead to third-party sites.