Security update for netty SUSE Patch security@suse.de SUSE Security Team openSUSE-SU-2021:0448-1 Final 1 1 2021-03-19T13:05:57Z current 2021-03-19T13:05:57Z 2021-03-19T13:05:57Z cve-database/bin/generate-cvrf.pl 2017-02-24T01:00:00Z Security update for netty This update for netty fixes the following issues: - CVE-2021-21295: Fixed an improper Content-Length header field validation (bsc#1183262). : This update was imported from the SUSE:SLE-15-SP2:Update update project. The CVRF data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0). openSUSE-2021-448 Copyright SUSE LLC under the Creative Commons License 4.0 with Attribution (CC-BY-4.0) https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/XDF63Q7PJ5ZO6J24Z3YJ7WWZWTTROVC2/ E-Mail link for openSUSE-SU-2021:0448-1 https://www.suse.com/support/security/rating/ SUSE Security Ratings https://bugzilla.suse.com/1183262 SUSE Bug 1183262 https://www.suse.com/security/cve/CVE-2021-21295/ SUSE CVE CVE-2021-21295 page openSUSE Leap 15.2 netty-4.1.13-lp152.3.3.1 netty-javadoc-4.1.13-lp152.3.3.1 netty-poms-4.1.13-lp152.3.3.1 netty-4.1.13-lp152.3.3.1 as a component of openSUSE Leap 15.2 netty-javadoc-4.1.13-lp152.3.3.1 as a component of openSUSE Leap 15.2 netty-poms-4.1.13-lp152.3.3.1 as a component of openSUSE Leap 15.2 Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.60.Final there is a vulnerability that enables request smuggling. If a Content-Length header is present in the original HTTP/2 request, the field is not validated by `Http2MultiplexHandler` as it is propagated up. This is fine as long as the request is not proxied through as HTTP/1.1. If the request comes in as an HTTP/2 stream, gets converted into the HTTP/1.1 domain objects (`HttpRequest`, `HttpContent`, etc.) via `Http2StreamFrameToHttpObjectCodec `and then sent up to the child channel's pipeline and proxied through a remote peer as HTTP/1.1 this may result in request smuggling. In a proxy case, users may assume the content-length is validated somehow, which is not the case. If the request is forwarded to a backend channel that is a HTTP/1.1 connection, the Content-Length now has meaning and needs to be checked. An attacker can smuggle requests inside the body as it gets downgraded from HTTP/2 to HTTP/1.1. For an example attack refer to the linked GitHub Advisory. Users are only affected if all of this is true: `HTTP2MultiplexCodec` or `Http2FrameCodec` is used, `Http2StreamFrameToHttpObjectCodec` is used to convert to HTTP/1.1 objects, and these HTTP/1.1 objects are forwarded to another remote peer. This has been patched in 4.1.60.Final As a workaround, the user can do the validation by themselves by implementing a custom `ChannelInboundHandler` that is put in the `ChannelPipeline` behind `Http2StreamFrameToHttpObjectCodec`. CVE-2021-21295 openSUSE Leap 15.2:netty-4.1.13-lp152.3.3.1 openSUSE Leap 15.2:netty-javadoc-4.1.13-lp152.3.3.1 openSUSE Leap 15.2:netty-poms-4.1.13-lp152.3.3.1 moderate 2.6 AV:N/AC:H/Au:N/C:N/I:P/A:N To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch". https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/XDF63Q7PJ5ZO6J24Z3YJ7WWZWTTROVC2/ https://www.suse.com/security/cve/CVE-2021-21295.html CVE-2021-21295 https://bugzilla.suse.com/1183262 SUSE Bug 1183262 https://bugzilla.suse.com/1184203 SUSE Bug 1184203