The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Rejected reason: Red Hat Product Security has determined that this CVE is not a security vulnerability.

A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading to unauthorized data access or modification. The main threat from this flaw impacts data confidentiality and integrity.

A vulnerability was found in Undertow where the ProxyProtocolReadListener reuses the same StringBuilder instance across multiple requests. This issue occurs when the parseProxyProtocolV1 method processes multiple requests on the same HTTP connection. As a result, different requests may share the same StringBuilder instance, potentially leading to information leakage between requests or responses. In some cases, a value from a previous request or response may be erroneously reused, which could lead to unintended data exposure. This issue primarily results in errors and connection termination but creates a risk of data leakage in multi-request environments.

A vulnerability was found in Undertow. This issue requires enabling the learning-push handler in the server's config, which is disabled by default, leaving the maxAge config in the handler unconfigured. The default is -1, which makes the handler vulnerable. If someone overwrites that config, the server is not subject to the attack. The attacker needs to be able to reach the server with a normal HTTP request.

A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.

A vulnerability was found in Undertow, where URL-encoded request paths can be mishandled during concurrent requests on the AJP listener. This issue arises because the same buffer is used to decode the paths for multiple requests simultaneously, leading to incorrect path information being processed. As a result, the server may attempt to access the wrong path, causing errors such as "404 Not Found" or other application failures. This flaw can potentially lead to a denial of service, as legitimate resources become inaccessible due to the path mix-up.

A vulnerability in the Eclipse Vert.x toolkit causes a memory leak in TCP servers configured with TLS and SNI support. When processing an unknown SNI server name assigned the default certificate instead of a mapped certificate, the SSL context is erroneously cached in the server name map, leading to memory exhaustion. This flaw allows attackers to send TLS client hello messages with fake server names, triggering a JVM out-of-memory error.

A vulnerability in the Eclipse Vert.x toolkit results in a memory leak due to using Netty FastThreadLocal data structures. Specifically, when the Vert.x HTTP client establishes connections to different hosts, triggering the memory leak. The leak can be accelerated with intimate runtime knowledge, allowing an attacker to exploit this vulnerability. For instance, a server accepting arbitrary internet addresses could serve as an attack vector by connecting to these addresses, thereby accelerating the memory leak.

A flaw was found in XNIO. The XNIO NotifierState that can cause a Stack Overflow Exception when the chain of notifier states becomes problematically large can lead to uncontrolled resource management and a possible denial of service (DoS).