CVE-2021-21295: Possible request smuggling in HTTP/2 due missing validation

Published Mar 9, 2021
·
Updated

Impact 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. A sample attack request looks like:

POST / HTTP/2 :authority:: externaldomain.com Content-Length: 4

asdfGET /evilRedirect HTTP/1.1 Host: internaldomain.com

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 These HTTP/1.1 objects are forwarded to another remote peer.

Patches This has been patched in 4.1.60.Final

Workarounds The user can do the validation by themselves by implementing a custom ChannelInboundHandler that is put in the ChannelPipeline behind Http2StreamFrameToHttpObjectCodec.

References Related change to workaround the problem: https://github.com/Netflix/zuul/pull/980

Other sources

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.

Affected Software

80 affected componentsFixes available
maven/io.netty:netty<4.0.0
maven/org.jboss.netty:netty<4.0.0
maven/io.netty:netty-codec-http2>=4.0.0<4.1.60.Final
4.1.60.Final
redhat/qpid-proton<0:0.33.0-6.el7_9
0:0.33.0-6.el7_9
redhat/qpid-proton<0:0.33.0-8.el8
0:0.33.0-8.el8
redhat/eap7-artemis-wildfly-integration<0:1.0.4-1.redhat_00001.1.el6ea
0:1.0.4-1.redhat_00001.1.el6ea
redhat/eap7-bouncycastle<0:1.68.0-2.redhat_00005.1.el6ea
0:1.68.0-2.redhat_00005.1.el6ea
redhat/eap7-hal-console<0:3.2.14-1.Final_redhat_00001.1.el6ea
0:3.2.14-1.Final_redhat_00001.1.el6ea
redhat/eap7-infinispan<0:9.4.22-3.Final_redhat_00001.1.el6ea
0:9.4.22-3.Final_redhat_00001.1.el6ea
redhat/eap7-ironjacamar<0:1.4.30-1.Final_redhat_00001.1.el6ea
0:1.4.30-1.Final_redhat_00001.1.el6ea
redhat/eap7-jboss-genericjms<0:2.0.9-1.Final_redhat_00001.1.el6ea
0:2.0.9-1.Final_redhat_00001.1.el6ea
redhat/eap7-jboss-marshalling<0:2.0.11-1.Final_redhat_00001.1.el6ea
0:2.0.11-1.Final_redhat_00001.1.el6ea
redhat/eap7-jboss-server-migration<0:1.7.2-6.Final_redhat_00007.1.el6ea
0:1.7.2-6.Final_redhat_00007.1.el6ea
redhat/eap7-jboss-weld<3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el6ea
3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el6ea
redhat/eap7-jgroups-kubernetes<0:1.0.16-1.Final_redhat_00001.1.el6ea
0:1.0.16-1.Final_redhat_00001.1.el6ea
redhat/eap7-netty<0:4.1.60-1.Final_redhat_00001.1.el6ea
0:4.1.60-1.Final_redhat_00001.1.el6ea
redhat/eap7-resteasy<0:3.11.4-1.Final_redhat_00001.1.el6ea
0:3.11.4-1.Final_redhat_00001.1.el6ea
redhat/eap7-undertow<0:2.0.35-1.SP1_redhat_00001.1.el6ea
0:2.0.35-1.SP1_redhat_00001.1.el6ea
redhat/eap7-velocity<0:2.3.0-1.redhat_00001.1.el6ea
0:2.3.0-1.redhat_00001.1.el6ea
redhat/eap7-weld-core<0:3.1.6-1.Final_redhat_00001.1.el6ea
0:3.1.6-1.Final_redhat_00001.1.el6ea
redhat/eap7-wildfly<0:7.3.7-1.GA_redhat_00002.1.el6ea
0:7.3.7-1.GA_redhat_00002.1.el6ea
redhat/eap7-wildfly-elytron<0:1.10.12-1.Final_redhat_00001.1.el6ea
0:1.10.12-1.Final_redhat_00001.1.el6ea
redhat/eap7-wildfly-http-client<0:1.0.26-1.Final_redhat_00001.1.el6ea
0:1.0.26-1.Final_redhat_00001.1.el6ea
redhat/eap7-xalan-j2<0:2.7.1-36.redhat_00013.1.el6ea
0:2.7.1-36.redhat_00013.1.el6ea
redhat/eap7-yasson<0:1.0.9-1.redhat_00001.1.el6ea
0:1.0.9-1.redhat_00001.1.el6ea
redhat/eap7-artemis-wildfly-integration<0:1.0.4-1.redhat_00001.1.el7ea
0:1.0.4-1.redhat_00001.1.el7ea
redhat/eap7-bouncycastle<0:1.68.0-2.redhat_00005.1.el7ea
0:1.68.0-2.redhat_00005.1.el7ea
redhat/eap7-hal-console<0:3.2.14-1.Final_redhat_00001.1.el7ea
0:3.2.14-1.Final_redhat_00001.1.el7ea
redhat/eap7-infinispan<0:9.4.22-3.Final_redhat_00001.1.el7ea
0:9.4.22-3.Final_redhat_00001.1.el7ea
redhat/eap7-ironjacamar<0:1.4.30-1.Final_redhat_00001.1.el7ea
0:1.4.30-1.Final_redhat_00001.1.el7ea
redhat/eap7-jboss-genericjms<0:2.0.9-1.Final_redhat_00001.1.el7ea
0:2.0.9-1.Final_redhat_00001.1.el7ea
redhat/eap7-jboss-marshalling<0:2.0.11-1.Final_redhat_00001.1.el7ea
0:2.0.11-1.Final_redhat_00001.1.el7ea
redhat/eap7-jboss-server-migration<0:1.7.2-6.Final_redhat_00007.1.el7ea
0:1.7.2-6.Final_redhat_00007.1.el7ea
redhat/eap7-jboss-weld<3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el7ea
3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el7ea
redhat/eap7-jgroups-kubernetes<0:1.0.16-1.Final_redhat_00001.1.el7ea
0:1.0.16-1.Final_redhat_00001.1.el7ea
redhat/eap7-netty<0:4.1.60-1.Final_redhat_00001.1.el7ea
0:4.1.60-1.Final_redhat_00001.1.el7ea
redhat/eap7-resteasy<0:3.11.4-1.Final_redhat_00001.1.el7ea
0:3.11.4-1.Final_redhat_00001.1.el7ea
redhat/eap7-undertow<0:2.0.35-1.SP1_redhat_00001.1.el7ea
0:2.0.35-1.SP1_redhat_00001.1.el7ea
redhat/eap7-velocity<0:2.3.0-1.redhat_00001.1.el7ea
0:2.3.0-1.redhat_00001.1.el7ea
redhat/eap7-weld-core<0:3.1.6-1.Final_redhat_00001.1.el7ea
0:3.1.6-1.Final_redhat_00001.1.el7ea
redhat/eap7-wildfly<0:7.3.7-1.GA_redhat_00002.1.el7ea
0:7.3.7-1.GA_redhat_00002.1.el7ea
redhat/eap7-wildfly-elytron<0:1.10.12-1.Final_redhat_00001.1.el7ea
0:1.10.12-1.Final_redhat_00001.1.el7ea
redhat/eap7-wildfly-http-client<0:1.0.26-1.Final_redhat_00001.1.el7ea
0:1.0.26-1.Final_redhat_00001.1.el7ea
redhat/eap7-xalan-j2<0:2.7.1-36.redhat_00013.1.el7ea
0:2.7.1-36.redhat_00013.1.el7ea
redhat/eap7-yasson<0:1.0.9-1.redhat_00001.1.el7ea
0:1.0.9-1.redhat_00001.1.el7ea
redhat/eap7-artemis-wildfly-integration<0:1.0.4-1.redhat_00001.1.el8ea
0:1.0.4-1.redhat_00001.1.el8ea
redhat/eap7-bouncycastle<0:1.68.0-2.redhat_00005.1.el8ea
0:1.68.0-2.redhat_00005.1.el8ea
redhat/eap7-hal-console<0:3.2.14-1.Final_redhat_00001.1.el8ea
0:3.2.14-1.Final_redhat_00001.1.el8ea
redhat/eap7-infinispan<0:9.4.22-3.Final_redhat_00001.1.el8ea
0:9.4.22-3.Final_redhat_00001.1.el8ea
redhat/eap7-ironjacamar<0:1.4.30-1.Final_redhat_00001.1.el8ea
0:1.4.30-1.Final_redhat_00001.1.el8ea
redhat/eap7-jboss-genericjms<0:2.0.9-1.Final_redhat_00001.1.el8ea
0:2.0.9-1.Final_redhat_00001.1.el8ea
redhat/eap7-jboss-marshalling<0:2.0.11-1.Final_redhat_00001.1.el8ea
0:2.0.11-1.Final_redhat_00001.1.el8ea
redhat/eap7-jboss-server-migration<0:1.7.2-6.Final_redhat_00007.1.el8ea
0:1.7.2-6.Final_redhat_00007.1.el8ea
redhat/eap7-jboss-weld<3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el8ea
3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el8ea
redhat/eap7-jgroups-kubernetes<0:1.0.16-1.Final_redhat_00001.1.el8ea
0:1.0.16-1.Final_redhat_00001.1.el8ea
redhat/eap7-netty<0:4.1.60-1.Final_redhat_00001.1.el8ea
0:4.1.60-1.Final_redhat_00001.1.el8ea
redhat/eap7-resteasy<0:3.11.4-1.Final_redhat_00001.1.el8ea
0:3.11.4-1.Final_redhat_00001.1.el8ea
redhat/eap7-undertow<0:2.0.35-1.SP1_redhat_00001.1.el8ea
0:2.0.35-1.SP1_redhat_00001.1.el8ea
redhat/eap7-velocity<0:2.3.0-1.redhat_00001.1.el8ea
0:2.3.0-1.redhat_00001.1.el8ea
redhat/eap7-weld-core<0:3.1.6-1.Final_redhat_00001.1.el8ea
0:3.1.6-1.Final_redhat_00001.1.el8ea
redhat/eap7-wildfly<0:7.3.7-1.GA_redhat_00002.1.el8ea
0:7.3.7-1.GA_redhat_00002.1.el8ea
redhat/eap7-wildfly-elytron<0:1.10.12-1.Final_redhat_00001.1.el8ea
0:1.10.12-1.Final_redhat_00001.1.el8ea
redhat/eap7-wildfly-http-client<0:1.0.26-1.Final_redhat_00001.1.el8ea
0:1.0.26-1.Final_redhat_00001.1.el8ea
redhat/eap7-xalan-j2<0:2.7.1-36.redhat_00013.1.el8ea
0:2.7.1-36.redhat_00013.1.el8ea
redhat/eap7-yasson<0:1.0.9-1.redhat_00001.1.el8ea
0:1.0.9-1.redhat_00001.1.el8ea
redhat/eap7-netty<0:4.1.63-1.Final_redhat_00001.1.el8ea
0:4.1.63-1.Final_redhat_00001.1.el8ea
redhat/eap7-netty<0:4.1.63-1.Final_redhat_00001.1.el7ea
0:4.1.63-1.Final_redhat_00001.1.el7ea
redhat/candlepin<0:4.1.13-1.el7
0:4.1.13-1.el7
redhat/candlepin<0:4.1.13-1.el8
0:4.1.13-1.el8
debian/netty
1:4.1.48-4+deb11u21:4.1.48-7+deb12u11:4.1.48-10
Netty Netty<4.1.60
NetApp OnCommand API Services
NetApp OnCommand Workflow Automation
Debian Debian Linux=10.0
Quarkus Quarkus<=1.13.7
Apache Kudu<1.16.0
Apache Zookeeper=3.5.9
Oracle Communications Cloud Native Core Policy=1.14.0
redhat/netty-codec-http<4.1.60.
4.1.60.
IBM watsonx.data intelligence<=5.2.0, 5.2.1, 5.2.2, 5.3.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade maven/io.netty:netty-codec-http2 to a version that resolves this vulnerability.

    Fixed in 4.1.60.Final
  2. Upgrade

    Upgrade redhat/qpid-proton to a version that resolves this vulnerability.

    Fixed in 0:0.33.0-6.el7_9
  3. Upgrade

    Upgrade redhat/qpid-proton to a version that resolves this vulnerability.

    Fixed in 0:0.33.0-8.el8
  4. Upgrade

    Upgrade redhat/eap7-artemis-wildfly-integration to a version that resolves this vulnerability.

    Fixed in 0:1.0.4-1.redhat_00001.1.el6ea
  5. Upgrade

    Upgrade redhat/eap7-bouncycastle to a version that resolves this vulnerability.

    Fixed in 0:1.68.0-2.redhat_00005.1.el6ea
  6. Upgrade

    Upgrade redhat/eap7-hal-console to a version that resolves this vulnerability.

    Fixed in 0:3.2.14-1.Final_redhat_00001.1.el6ea
  7. Upgrade

    Upgrade redhat/eap7-infinispan to a version that resolves this vulnerability.

    Fixed in 0:9.4.22-3.Final_redhat_00001.1.el6ea
  8. Upgrade

    Upgrade redhat/eap7-ironjacamar to a version that resolves this vulnerability.

    Fixed in 0:1.4.30-1.Final_redhat_00001.1.el6ea
  9. Upgrade

    Upgrade redhat/eap7-jboss-genericjms to a version that resolves this vulnerability.

    Fixed in 0:2.0.9-1.Final_redhat_00001.1.el6ea
  10. Upgrade

    Upgrade redhat/eap7-jboss-marshalling to a version that resolves this vulnerability.

    Fixed in 0:2.0.11-1.Final_redhat_00001.1.el6ea
  11. Upgrade

    Upgrade redhat/eap7-jboss-server-migration to a version that resolves this vulnerability.

    Fixed in 0:1.7.2-6.Final_redhat_00007.1.el6ea
  12. Upgrade

    Upgrade redhat/eap7-jboss-weld to a version that resolves this vulnerability.

    Fixed in 3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el6ea
  13. Upgrade

    Upgrade redhat/eap7-jgroups-kubernetes to a version that resolves this vulnerability.

    Fixed in 0:1.0.16-1.Final_redhat_00001.1.el6ea
  14. Upgrade

    Upgrade redhat/eap7-netty to a version that resolves this vulnerability.

    Fixed in 0:4.1.60-1.Final_redhat_00001.1.el6ea
  15. Upgrade

    Upgrade redhat/eap7-resteasy to a version that resolves this vulnerability.

    Fixed in 0:3.11.4-1.Final_redhat_00001.1.el6ea
  16. Upgrade

    Upgrade redhat/eap7-undertow to a version that resolves this vulnerability.

    Fixed in 0:2.0.35-1.SP1_redhat_00001.1.el6ea
  17. Upgrade

    Upgrade redhat/eap7-velocity to a version that resolves this vulnerability.

    Fixed in 0:2.3.0-1.redhat_00001.1.el6ea
  18. Upgrade

    Upgrade redhat/eap7-weld-core to a version that resolves this vulnerability.

    Fixed in 0:3.1.6-1.Final_redhat_00001.1.el6ea
  19. Upgrade

    Upgrade redhat/eap7-wildfly to a version that resolves this vulnerability.

    Fixed in 0:7.3.7-1.GA_redhat_00002.1.el6ea
  20. Upgrade

    Upgrade redhat/eap7-wildfly-elytron to a version that resolves this vulnerability.

    Fixed in 0:1.10.12-1.Final_redhat_00001.1.el6ea
  21. Upgrade

    Upgrade redhat/eap7-wildfly-http-client to a version that resolves this vulnerability.

    Fixed in 0:1.0.26-1.Final_redhat_00001.1.el6ea
  22. Upgrade

    Upgrade redhat/eap7-xalan-j2 to a version that resolves this vulnerability.

    Fixed in 0:2.7.1-36.redhat_00013.1.el6ea
  23. Upgrade

    Upgrade redhat/eap7-yasson to a version that resolves this vulnerability.

    Fixed in 0:1.0.9-1.redhat_00001.1.el6ea
  24. Upgrade

    Upgrade redhat/eap7-artemis-wildfly-integration to a version that resolves this vulnerability.

    Fixed in 0:1.0.4-1.redhat_00001.1.el7ea
  25. Upgrade

    Upgrade redhat/eap7-bouncycastle to a version that resolves this vulnerability.

    Fixed in 0:1.68.0-2.redhat_00005.1.el7ea
  26. Upgrade

    Upgrade redhat/eap7-hal-console to a version that resolves this vulnerability.

    Fixed in 0:3.2.14-1.Final_redhat_00001.1.el7ea
  27. Upgrade

    Upgrade redhat/eap7-infinispan to a version that resolves this vulnerability.

    Fixed in 0:9.4.22-3.Final_redhat_00001.1.el7ea
  28. Upgrade

    Upgrade redhat/eap7-ironjacamar to a version that resolves this vulnerability.

    Fixed in 0:1.4.30-1.Final_redhat_00001.1.el7ea
  29. Upgrade

    Upgrade redhat/eap7-jboss-genericjms to a version that resolves this vulnerability.

    Fixed in 0:2.0.9-1.Final_redhat_00001.1.el7ea
  30. Upgrade

    Upgrade redhat/eap7-jboss-marshalling to a version that resolves this vulnerability.

    Fixed in 0:2.0.11-1.Final_redhat_00001.1.el7ea
  31. Upgrade

    Upgrade redhat/eap7-jboss-server-migration to a version that resolves this vulnerability.

    Fixed in 0:1.7.2-6.Final_redhat_00007.1.el7ea
  32. Upgrade

    Upgrade redhat/eap7-jboss-weld to a version that resolves this vulnerability.

    Fixed in 3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el7ea
  33. Upgrade

    Upgrade redhat/eap7-jgroups-kubernetes to a version that resolves this vulnerability.

    Fixed in 0:1.0.16-1.Final_redhat_00001.1.el7ea
  34. Upgrade

    Upgrade redhat/eap7-netty to a version that resolves this vulnerability.

    Fixed in 0:4.1.60-1.Final_redhat_00001.1.el7ea
  35. Upgrade

    Upgrade redhat/eap7-resteasy to a version that resolves this vulnerability.

    Fixed in 0:3.11.4-1.Final_redhat_00001.1.el7ea
  36. Upgrade

    Upgrade redhat/eap7-undertow to a version that resolves this vulnerability.

    Fixed in 0:2.0.35-1.SP1_redhat_00001.1.el7ea
  37. Upgrade

    Upgrade redhat/eap7-velocity to a version that resolves this vulnerability.

    Fixed in 0:2.3.0-1.redhat_00001.1.el7ea
  38. Upgrade

    Upgrade redhat/eap7-weld-core to a version that resolves this vulnerability.

    Fixed in 0:3.1.6-1.Final_redhat_00001.1.el7ea
  39. Upgrade

    Upgrade redhat/eap7-wildfly to a version that resolves this vulnerability.

    Fixed in 0:7.3.7-1.GA_redhat_00002.1.el7ea
  40. Upgrade

    Upgrade redhat/eap7-wildfly-elytron to a version that resolves this vulnerability.

    Fixed in 0:1.10.12-1.Final_redhat_00001.1.el7ea
  41. Upgrade

    Upgrade redhat/eap7-wildfly-http-client to a version that resolves this vulnerability.

    Fixed in 0:1.0.26-1.Final_redhat_00001.1.el7ea
  42. Upgrade

    Upgrade redhat/eap7-xalan-j2 to a version that resolves this vulnerability.

    Fixed in 0:2.7.1-36.redhat_00013.1.el7ea
  43. Upgrade

    Upgrade redhat/eap7-yasson to a version that resolves this vulnerability.

    Fixed in 0:1.0.9-1.redhat_00001.1.el7ea
  44. Upgrade

    Upgrade redhat/eap7-artemis-wildfly-integration to a version that resolves this vulnerability.

    Fixed in 0:1.0.4-1.redhat_00001.1.el8ea
  45. Upgrade

    Upgrade redhat/eap7-bouncycastle to a version that resolves this vulnerability.

    Fixed in 0:1.68.0-2.redhat_00005.1.el8ea
  46. Upgrade

    Upgrade redhat/eap7-hal-console to a version that resolves this vulnerability.

    Fixed in 0:3.2.14-1.Final_redhat_00001.1.el8ea
  47. Upgrade

    Upgrade redhat/eap7-infinispan to a version that resolves this vulnerability.

    Fixed in 0:9.4.22-3.Final_redhat_00001.1.el8ea
  48. Upgrade

    Upgrade redhat/eap7-ironjacamar to a version that resolves this vulnerability.

    Fixed in 0:1.4.30-1.Final_redhat_00001.1.el8ea
  49. Upgrade

    Upgrade redhat/eap7-jboss-genericjms to a version that resolves this vulnerability.

    Fixed in 0:2.0.9-1.Final_redhat_00001.1.el8ea
  50. Upgrade

    Upgrade redhat/eap7-jboss-marshalling to a version that resolves this vulnerability.

    Fixed in 0:2.0.11-1.Final_redhat_00001.1.el8ea
  51. Upgrade

    Upgrade redhat/eap7-jboss-server-migration to a version that resolves this vulnerability.

    Fixed in 0:1.7.2-6.Final_redhat_00007.1.el8ea
  52. Upgrade

    Upgrade redhat/eap7-jboss-weld to a version that resolves this vulnerability.

    Fixed in 3.1-api-0:3.1.0-6.SP3_redhat_00001.1.el8ea
  53. Upgrade

    Upgrade redhat/eap7-jgroups-kubernetes to a version that resolves this vulnerability.

    Fixed in 0:1.0.16-1.Final_redhat_00001.1.el8ea
  54. Upgrade

    Upgrade redhat/eap7-netty to a version that resolves this vulnerability.

    Fixed in 0:4.1.60-1.Final_redhat_00001.1.el8ea
  55. Upgrade

    Upgrade redhat/eap7-resteasy to a version that resolves this vulnerability.

    Fixed in 0:3.11.4-1.Final_redhat_00001.1.el8ea
  56. Upgrade

    Upgrade redhat/eap7-undertow to a version that resolves this vulnerability.

    Fixed in 0:2.0.35-1.SP1_redhat_00001.1.el8ea
  57. Upgrade

    Upgrade redhat/eap7-velocity to a version that resolves this vulnerability.

    Fixed in 0:2.3.0-1.redhat_00001.1.el8ea
  58. Upgrade

    Upgrade redhat/eap7-weld-core to a version that resolves this vulnerability.

    Fixed in 0:3.1.6-1.Final_redhat_00001.1.el8ea
  59. Upgrade

    Upgrade redhat/eap7-wildfly to a version that resolves this vulnerability.

    Fixed in 0:7.3.7-1.GA_redhat_00002.1.el8ea
  60. Upgrade

    Upgrade redhat/eap7-wildfly-elytron to a version that resolves this vulnerability.

    Fixed in 0:1.10.12-1.Final_redhat_00001.1.el8ea
  61. Upgrade

    Upgrade redhat/eap7-wildfly-http-client to a version that resolves this vulnerability.

    Fixed in 0:1.0.26-1.Final_redhat_00001.1.el8ea
  62. Upgrade

    Upgrade redhat/eap7-xalan-j2 to a version that resolves this vulnerability.

    Fixed in 0:2.7.1-36.redhat_00013.1.el8ea
  63. Upgrade

    Upgrade redhat/eap7-yasson to a version that resolves this vulnerability.

    Fixed in 0:1.0.9-1.redhat_00001.1.el8ea
  64. Upgrade

    Upgrade redhat/eap7-netty to a version that resolves this vulnerability.

    Fixed in 0:4.1.63-1.Final_redhat_00001.1.el8ea
  65. Upgrade

    Upgrade redhat/eap7-netty to a version that resolves this vulnerability.

    Fixed in 0:4.1.63-1.Final_redhat_00001.1.el7ea
  66. Upgrade

    Upgrade redhat/candlepin to a version that resolves this vulnerability.

    Fixed in 0:4.1.13-1.el7
  67. Upgrade

    Upgrade redhat/candlepin to a version that resolves this vulnerability.

    Fixed in 0:4.1.13-1.el8
  68. Upgrade

    Upgrade debian/netty to a version that resolves this vulnerability.

    Fixed in 1:4.1.48-4+deb11u2Fixed in 1:4.1.48-7+deb12u1Fixed in 1:4.1.48-10
  69. Upgrade

    Upgrade redhat/netty-codec-http to a version that resolves this vulnerability.

    Fixed in 4.1.60.
  70. Upgrade

    Upgrade io.netty:netty-codec-http2 to a version that resolves this vulnerability.

    Fixed in 4.1.60.Final
  71. Configuration

    If you cannot upgrade, implement a custom ChannelInboundHandler and insert it in the ChannelPipeline behind `Http2StreamFrameToHttpObjectCodec` to perform Content-Length validation, because Content-Length from the original HTTP/2 request is propagated without validation and can enable request smuggling when forwarded to a backend over HTTP/1.1.

    Netty HTTP/2-to-HTTP/1.1 conversion pipeline ChannelPipeline behind Http2StreamFrameToHttpObjectCodec = Add a custom ChannelInboundHandler to validate Content-Length (and ensure it is checked before forwarding/proxying as HTTP/1.1)

Event History

Mar 9, 2021
CVE Published
12:00 AM
CVE Published
via MITRE·06:35 PM
Data Sourced
via MITRE·06:35 PM
DescriptionSeverityWeakness
Advisory Published
06:49 PM
Mar 10, 2021
Data Sourced
via Red Hat·01:34 PM
DescriptionSeverityAffected Software
Jan 11, 2024
Data Sourced
via Launchpad·11:54 PM
Description
Sep 16, 2024
Data Sourced
via Ubuntu·02:30 AM
RemedyDescriptionSeverityAffected Software
Jun 24, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2021-21295?

CVE-2021-21295 is classified as a moderate severity vulnerability.

2

How do I fix CVE-2021-21295?

To fix CVE-2021-21295, update to Netty version 4.1.60.Final or a later version.

3

What are the affected versions for CVE-2021-21295?

CVE-2021-21295 affects Netty versions up to 4.0.x.

4

Is CVE-2021-21295 present in my application?

CVE-2021-21295 may be present if your application uses affected versions of the Netty library.

5

What is the impact of CVE-2021-21295?

CVE-2021-21295 can lead to improper handling of the Content-Length header in HTTP/2 requests when proxied.

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