Netty project is an event-driven asynchronous network application framework. Starting in version 4.1.83.Final and prior to 4.1.86.Final, when calling `DefaultHttpHeadesr.set` with an _iterator_ of values, header value validation was not performed, allowing malicious header values in the iterator to perform HTTP Response Splitting. This issue has been patched in version 4.1.86.Final. Integrators can work around the issue by changing the `DefaultHttpHeaders.set(CharSequence, Iterator<?>)` call, into a `remove()` call, and call `add()` in a loop over the iterator of values.

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.128.Final and 4.2.7.Final, the SMTP codec in Netty contains an SMTP command injection vulnerability due to insufficient input validation for Carriage Return (\r) and Line Feed (\n) characters in user-supplied parameters. The vulnerability exists in io.netty.handler.codec.smtp.DefaultSmtpRequest, where parameters are directly concatenated into the SMTP command string without sanitization. When methods such as SmtpRequests.rcpt(recipient) are called with a malicious string containing CRLF sequences, attackers can inject arbitrary SMTP commands. Because the injected commands are sent from the server's trusted IP address, resulting emails will likely pass SPF and DKIM authentication checks, making them appear legitimate. This allows remote attackers who can control SMTP command parameters (such as email recipients) to forge arbitrary emails from the trusted server, potentially impersonating executives and forging high-stakes corporate communications. This issue has been patched in versions 4.1.129.Final and 4.2.8.Final. No known workarounds exist.

Undici is an HTTP/1.1 client for Node.js. Starting with version 2.0.0 and prior to version 5.19.1, the undici library does not protect `host` HTTP header from CRLF injection vulnerabilities. This issue is patched in Undici v5.19.1. As a workaround, sanitize the `headers.host` string before passing to undici.

A CRLF injection vulnerability in Kentico Xperience allows attackers to manipulate URL query string redirects via improper encoding in the routing engine. This could enable header injection and potentially facilitate further web application attacks.

undici is an HTTP/1.1 client, written from scratch for Node.js. It is possible to inject CRLF sequences into request headers in undici in versions less than 5.7.1. A fix was released in version 5.8.0. Sanitizing all HTTP headers from untrusted sources to eliminate `\r\n` is a workaround for this issue.