Описание
Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature
Summary
Netty HTTP/2 max header size handling produces attack similar to HTTP/2 Rapid Reset.
Details
There is a setting in the http2 specification called SETTINGS_MAX_HEADER_LIST_SIZE. According to the RFC: “This advisory setting informs a peer of the maximum field section size that the sender is prepared to accept, in units of octets.”
When a client sends that setting to Netty, it appears that Netty will behave as follows:
- Read the request
- Proxy the request to the origin
- Attempt to produce a response
- Create an exception while writing the headers for the response
Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature.
Remediation
When speaking with clients, Netty should potentially treat this as “advisory” and ignore it. It would be best to ignore the SETTINGS_MAX_HEADER_LIST_SIZE setting from clients (or ignore it when sending to clients). According to the spec, a server does not need to honor this advisory setting, and it appears that other http/2 implementations ignore it when acting as a server.
Impact
This is a DDoS attack similar to the HTTP/2 Rapid Reset Attack.
Credit
Jonathan Looney (Engineering, Netflix)
Contact
Ashley Tolbert (Security, Netflix) - artolbert@netflix.com
Ссылки
- https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm
- https://nvd.nist.gov/vuln/detail/CVE-2026-50560
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings
Пакеты
io.netty:netty-codec-http2
>= 4.2.0.Final, <= 4.2.14.Final
4.2.15.Final
io.netty:netty-codec-http2
<= 4.1.134.Final
4.1.135.Final
Связанные уязвимости
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Netty is a network application framework for development of protocol s ...
