Withdrawn by the publisher.

Affected: CleanStart: keycloak

Multiple security vulnerabilities affect the keycloak package. These issues are resolved in later releases. See references for individual vulnerability details.

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, DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Affected: Maven: io.netty:netty-codec-http2

### Impact DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work.

### Resources https://www.rfc-editor.org/rfc/rfc7540.html#section-6.5.2

netty-4.1.135-1.1 on GA media

eclipse-vertx/vert.x: eclipse-vertx/vert.x: Denial of Service via TLS handshake with wildcard server name netty-handler: netty-handler: IPv6 subnet rule bypass due to incorrect masking operation netty-codec-haproxy: Netty-codec-haproxy: Denial of Service via malformed HAProxy message netty-handler: Netty: Denial of Service due to eager buffer allocation in TLS handshake netty-resolver-dns: Netty DNS resolver: DNS Cache Poisoning via predictable transaction IDs netty-resolver-dns: Netty: Information disclosure and data manipulation due to improper CNAME record validation netty-codec-http2: Netty: Denial of Service via uncontrolled HTTP/2 concurrent streams io.netty/netty-resolver-dns: Netty has Insufficient Bailiwick Validation for NS Records netty-codec-http2: netty-codec-http2: Denial of Service due to resource leak netty-codec-haproxy: Netty HAProxy PROXY protocol v2 codec: Denial of Service via memory leak from crafted PROXY protocol headers netty-handler: Netty: Improper trust manager handling leads to hostname verification bypass netty-codec-http: Netty: Data manipulation via request-boundary confusion in HttpObjectDecoder io.quarkus/quarkus-vertx-http: Quarkus: Authorization bypass in HTTP path-based policies via encoded characters netty-codec-http2: Netty: Denial of Service due to HTTP/2 max header size handling

Affected: Ubuntu:Pro:14.04:LTS: netty, Ubuntu:Pro:16.04:LTS: netty, Ubuntu:Pro:18.04:LTS: netty, Ubuntu:Pro:20.04:LTS: netty, Ubuntu:Pro:22.04:LTS: netty, Ubuntu:Pro:24.04:LTS: netty, Ubuntu:25.10: netty, Ubuntu:Pro:26.04:LTS: netty

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, DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitsvorkehrungen zu umgehen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand herbeizuführen.