CVE Vulnerabilities

CVE-2021-21295

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Published: Mar 09, 2021 | Modified: Nov 07, 2023
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
2.6 LOW
AV:N/AC:H/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
5.9 MODERATE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Ubuntu
MEDIUM

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 channels 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.

Weakness

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

Affected Software

Name Vendor Start Version End Version
Netty Netty * 4.1.60 (excluding)
AMQ Clients 2.y for RHEL 7 RedHat qpid-proton-0:0.33.0-6.el7_9 *
AMQ Clients 2.y for RHEL 8 RedHat qpid-proton-0:0.33.0-8.el8 *
EAP 7.4.1 release RedHat *
Red Hat AMQ 7.8.2 RedHat netty *
Red Hat AMQ 7.9.0 RedHat netty *
Red Hat AMQ Online 1.7.0 GA RedHat netty *
Red Hat AMQ Streams 1.8.0 RedHat netty *
Red Hat build of Eclipse Vert.x 4.0.3 RedHat netty *
Red Hat build of Quarkus 2.2.3 RedHat netty *
Red Hat Data Grid 8.2.0 RedHat netty *
Red Hat EAP-XP 2.0.0 via EAP 7.3.x base RedHat netty *
Red Hat Fuse 7.10 RedHat netty *
Red Hat JBoss Enterprise Application Platform 7 RedHat netty *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-artemis-wildfly-integration-0:1.0.4-1.redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-bouncycastle-0:1.68.0-2.redhat_00005.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-hal-console-0:3.2.14-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-infinispan-0:9.4.22-3.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-ironjacamar-0:1.4.30-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-jboss-genericjms-0:2.0.9-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-jboss-marshalling-0:2.0.11-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-jboss-server-migration-0:1.7.2-6.Final_redhat_00007.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-jboss-weld-3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-jgroups-kubernetes-0:1.0.16-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-mod_cluster-0:1.4.3-2.Final_redhat_00002.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-netty-0:4.1.60-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-resteasy-0:3.11.4-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-undertow-0:2.0.35-1.SP1_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-velocity-0:2.3.0-1.redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-weld-core-0:3.1.6-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-wildfly-0:7.3.7-1.GA_redhat_00002.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-wildfly-elytron-0:1.10.12-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-wildfly-http-client-0:1.0.26-1.Final_redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-xalan-j2-0:2.7.1-36.redhat_00013.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6 RedHat eap7-yasson-0:1.0.9-1.redhat_00001.1.el6eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-artemis-wildfly-integration-0:1.0.4-1.redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-bouncycastle-0:1.68.0-2.redhat_00005.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-hal-console-0:3.2.14-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-infinispan-0:9.4.22-3.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-ironjacamar-0:1.4.30-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-jboss-genericjms-0:2.0.9-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-jboss-marshalling-0:2.0.11-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-jboss-server-migration-0:1.7.2-6.Final_redhat_00007.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-jboss-weld-3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-jgroups-kubernetes-0:1.0.16-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-mod_cluster-0:1.4.3-2.Final_redhat_00002.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-netty-0:4.1.60-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-resteasy-0:3.11.4-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-undertow-0:2.0.35-1.SP1_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-velocity-0:2.3.0-1.redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-weld-core-0:3.1.6-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-wildfly-0:7.3.7-1.GA_redhat_00002.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-wildfly-elytron-0:1.10.12-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-wildfly-http-client-0:1.0.26-1.Final_redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-xalan-j2-0:2.7.1-36.redhat_00013.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7 RedHat eap7-yasson-0:1.0.9-1.redhat_00001.1.el7eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-artemis-wildfly-integration-0:1.0.4-1.redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-bouncycastle-0:1.68.0-2.redhat_00005.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-hal-console-0:3.2.14-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-infinispan-0:9.4.22-3.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-ironjacamar-0:1.4.30-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-jboss-genericjms-0:2.0.9-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-jboss-marshalling-0:2.0.11-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-jboss-server-migration-0:1.7.2-6.Final_redhat_00007.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-jboss-weld-3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-jgroups-kubernetes-0:1.0.16-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-mod_cluster-0:1.4.3-2.Final_redhat_00002.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-netty-0:4.1.60-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-resteasy-0:3.11.4-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-undertow-0:2.0.35-1.SP1_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-velocity-0:2.3.0-1.redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-weld-core-0:3.1.6-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-wildfly-0:7.3.7-1.GA_redhat_00002.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-wildfly-elytron-0:1.10.12-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-wildfly-http-client-0:1.0.26-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-xalan-j2-0:2.7.1-36.redhat_00013.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8 RedHat eap7-yasson-0:1.0.9-1.redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8 RedHat eap7-netty-0:4.1.63-1.Final_redhat_00001.1.el8eap *
Red Hat JBoss Enterprise Application Platform 7.4 on RHEL 7 RedHat eap7-netty-0:4.1.63-1.Final_redhat_00001.1.el7eap *
Red Hat Satellite 6.11 for RHEL 7 RedHat candlepin-0:4.1.13-1.el7sat *
Red Hat Satellite 6.11 for RHEL 8 RedHat candlepin-0:4.1.13-1.el8sat *
Red Hat Single Sign-On 7.4.7 RedHat netty *
Netty Ubuntu bionic *
Netty Ubuntu esm-apps/bionic *
Netty Ubuntu esm-apps/focal *
Netty Ubuntu esm-apps/xenial *
Netty Ubuntu groovy *
Netty Ubuntu hirsute *
Netty Ubuntu impish *
Netty Ubuntu jammy *
Netty Ubuntu kinetic *
Netty Ubuntu lunar *
Netty Ubuntu mantic *
Netty Ubuntu trusty *
Netty Ubuntu xenial *

Extended Description

HTTP requests or responses (“messages”) can be malformed or unexpected in ways that cause web servers or clients to interpret the messages in different ways than intermediary HTTP agents such as load balancers, reverse proxies, web caching proxies, application firewalls, etc. For example, an adversary may be able to add duplicate or different header fields that a client or server might interpret as one set of messages, whereas the intermediary might interpret the same sequence of bytes as a different set of messages. For example, discrepancies can arise in how to handle duplicate headers like two Transfer-encoding (TE) or two Content-length (CL), or the malicious HTTP message will have different headers for TE and CL. The inconsistent parsing and interpretation of messages can allow the adversary to “smuggle” a message to the client/server without the intermediary being aware of it. This weakness is usually the result of the usage of outdated or incompatible HTTP protocol versions in the HTTP agents.

Potential Mitigations

References