(Netty is an asynchronous, event-driven network application framework. ...)

A flaw was found in the Netty netty-codec-http component. A remote attacker can send HTTP requests containing highly compressed data. The HTTP decoder in netty-codec-http fails to properly limit the decompression of this content, causing the system to consume excessive memory. This can lead to memory exhaustion and a denial of service (DoS), making the service unavailable to legitimate users.

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, `HttpContentEncoder` (the superclass of the production handler `HttpContentCompressor`) maintains a per-channel `ArrayDeque<CharSequence>` named `acceptEncodingQueue` that accumulates attacker-controlled data without any size limit. The queue is filled on the I/O thread for every inbound HTTP request and drained only when the application later writes a non-1xx response. This creates a resource exhaustion vulnerability when an attacker exploits HTTP/1.1 pipelining to flood the connection with requests faster than the application produces responses. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

Netty is an asynchronous, event-driven network application framework. ...

Netty: [HttpContentEncoder] Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining Leads to Denial of Service