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Tracking
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| Source | ID | Title |
|---|---|---|
Debian DSA |
DSA-4885-1 | netty security update |
EUVD |
EUVD-2021-0719 | 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`. |
Github GHSA |
GHSA-wm47-8v5p-wjpj | Possible request smuggling in HTTP/2 due missing validation |
Ubuntu USN |
USN-6049-1 | Netty vulnerabilities |
No history.
Subscriptions
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2024-08-03T18:09:15.344Z
Reserved: 2020-12-22T00:00:00.000Z
Link: CVE-2021-21295
No data.
Status : Modified
Published: 2021-03-09T19:15:12.657
Modified: 2026-06-17T03:35:13.370
Link: CVE-2021-21295
OpenCVE Enrichment
No data.
-
CWE-444
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Debian DSA
EUVD
Github GHSA
Ubuntu USN