Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
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 | * | 4.1.133 (excluding) |
| Netty | Netty | 4.2.0 (including) | 4.2.13 (excluding) |
| Cryostat 4 on RHEL 9 | RedHat | cryostat/cryostat-reports-rhel9:4.2.0-10 | * |
| Cryostat 4 on RHEL 9 | RedHat | cryostat/cryostat-rhel9:4.2.0-10 | * |
| Cryostat 4 on RHEL 9 | RedHat | cryostat/jfr-datasource-rhel9:4.2.0-10 | * |
| Red Hat build of Quarkus 3.27.4 | RedHat | netty-codec-http | * |
| Red Hat build of Quarkus 3.33.2 | RedHat | * | |
| Red Hat OpenShift Dev Spaces 3.28 | RedHat | devspaces/openvsx-rhel9:1780948325 | * |
| Red Hat OpenShift Dev Spaces 3.28 | RedHat | devspaces/pluginregistry-rhel9:1780696380 | * |
| Red Hat OpenShift Dev Spaces 3.28 | RedHat | devspaces/server-rhel9:1780694994 | * |
| Netty | Ubuntu | devel | * |
| Netty | Ubuntu | esm-apps-legacy/xenial | * |
| Netty | Ubuntu | esm-apps/bionic | * |
| Netty | Ubuntu | esm-apps/focal | * |
| Netty | Ubuntu | esm-apps/jammy | * |
| Netty | Ubuntu | esm-apps/noble | * |
| Netty | Ubuntu | esm-apps/resolute | * |
| Netty | Ubuntu | esm-infra-legacy/trusty | * |
| Netty | Ubuntu | jammy | * |
| Netty | Ubuntu | noble | * |
| Netty | Ubuntu | questing | * |
| Netty | Ubuntu | resolute | * |
| Netty | Ubuntu | upstream | * |
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.