| Descripción: | Summary:
The remote host is missing an update for the 'netty' package(s) announced via the MGASA-2021-0374 advisory.
Vulnerability Insight:
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).
In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is a
vulnerability that enables request smuggling. The content-length header is not
correctly validated if the request only uses a single Http2HeaderFrame with
the endStream set to true. This could lead to request smuggling if the
request is proxied to a remote peer and translated to HTTP/1.1. This is a
followup of GHSA-wm47-8v5p-wjpj/CVE-2021-21295 which did miss to fix this one
case. This was fixed as part of 4.1.61.Final
(CVE-2021-21409).
Affected Software/OS:
'netty' package(s) on Mageia 8.
Solution:
Please install the updated package(s).
CVSS Score:
4.3
CVSS Vector:
AV:N/AC:M/Au:N/C:N/I:P/A:N
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