HTTP Request Smuggling Affecting io.netty:netty-codec-http2 Open this link in a new tab package, versions [,4.1.61.Final)

  • Attack Complexity


  • Integrity


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  • snyk-id


  • published

    31 Mar 2021

  • disclosed

    31 Mar 2021

  • credit


How to fix?

Upgrade io.netty:netty-codec-http2 to version 4.1.61.Final or higher.


io.netty:netty-codec-http2 is a HTTP2 sub package for the netty library, an event-driven asynchronous network application framework.

Affected versions of this package are vulnerable to HTTP Request Smuggling. The content-length header is not correctly validated if the request only uses a single Http2HeaderFrame with the endStream set to true. This could lead to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. This is a follow-up of CVE-2021-21295 which did not fix this specific case.