In Eclipse Jetty versions 12.0.0 to 12.0.16 included, an HTTP/2 client can specify a very large value for the HTTP/2 settings parameter SETTINGSMAXHEADERLISTSIZE. The Jetty HTTP/2 server does not perform validation on this setting, and tries to allocate a ByteBuffer of the specified capacity to encode HTTP responses, likely resulting in OutOfMemoryError being thrown, or even the JVM process exiting.

There exists a security vulnerability in Jetty's DosFilter which can be exploited by unauthorized users to cause remote denial-of-service (DoS) attack on the server using DosFilter. By repeatedly sending crafted requests, attackers can trigger OutofMemory errors and exhaust the server's memory finally.

There exists a security vulnerability in Jetty's ThreadLimitHandler.getRemote() which can be exploited by unauthorized users to cause remote denial-of-service (DoS) attack. By repeatedly sending crafted requests, attackers can trigger OutofMemory errors and exhaust the server's memory.

Impact Jetty PushSessionCacheFilter can be exploited by unauthenticated users to launch remote DoS attacks by exhausting the server’s memory.

Patches https://github.com/jetty/jetty.project/pull/9715 https://github.com/jetty/jetty.project/pull/9716

Workarounds The session usage is intrinsic to the design of the PushCacheFilter. The issue can be avoided by: + not using the PushCacheFilter. Push has been deprecated by the various IETF specs and early hints responses should be used instead. + reducing the reducing the idle timeout on unauthenticated sessions will reduce the time such session stay in memory. + configuring a session cache to use session passivation, so that sessions are not stored in memory, but rather in a database or file system that may have significantly more capacity than memory.

References https://github.com/jetty/jetty.project/pull/10756 https://github.com/jetty/jetty.project/pull/10755

Jetty is a Java based web server and servlet engine. An HTTP/2 SSL connection that is established and TCP congested will be leaked when it times out. An attacker can cause many connections to end up in this state, and the server may run out of file descriptors, eventually causing the server to stop accepting new connections from valid clients. The vulnerability is patched in 9.4.54, 10.0.20, 11.0.20, and 12.0.6.

https://github.com/jetty/jetty.project/issues/11256 https://github.com/jetty/jetty.project/security/advisories/GHSA-rggv-cv7r-mw98

[I've seen multiple news articles & blogs in the wake of the coordinated disclosure today, but no postings here yet, so lets start fixing that.]

Google, Cloudflare, AWS, and others released details today of a protocol-level issue in HTTP/2 being exploited in recent months for denial-of-service attacks:

https://cloud.google.com/blog/products/identity-security/how-it-works-the-novel-http2-rapid-reset-ddos-attack https://blog.cloudflare.com/technical-breakdown-http2-rapid-reset-ddos-attack/ https://aws.amazon.com/blogs/security/how-aws-protects-customers-from-ddos-events/

This attack works via the multiplexed streams feature of HTTP/2, in which the client repeatedly makes a request for a new stream, and then immediately sends a RSTSTREAM frame to cancel them, resulting in the server doing lots of extra work to set up and tear down the streams, while not hitting any server-side limit on a maximum number of active streams per connection.

CVE-2023-44487 was issued to track this issue across implementations: https://www.cve.org/CVERecord?id=CVE-2023-44487

A script to check for affected implemenations has been posted at: https://github.com/bcdannyboy/CVE-2023-44487

Information I've found so far on open source implementations (most via the current listings in the CVE) include:

- Apache httpd: https://chaos.social/@icing/111210915918780532

- caddy: https://github.com/caddyserver/caddy/issues/5877

- envoy: https://github.com/envoyproxy/envoy/pull/30055

- golang: https://github.com/golang/go/issues/63417 https://groups.google.com/g/golang-announce/c/iNNxDTCjZvo

- h2o: https://github.com/h2o/h2o/security/advisories/GHSA-2m7v-gc89-fjqf https://github.com/h2o/h2o/pull/3291

- haproxy: https://github.com/haproxy/haproxy/issues/2312

- hyper: https://seanmonstar.com/post/730794151136935936/hyper-http2-rapid-reset-unaffected

- jetty: https://github.com/eclipse/jetty.project/issues/10679 https://github.com/eclipse/jetty.project/releases/tag/jetty-12.0.2 https://github.com/eclipse/jetty.project/releases/tag/jetty-11.0.17 https://github.com/eclipse/jetty.project/releases/tag/jetty-10.0.17 https://github.com/eclipse/jetty.project/releases/tag/jetty-9.4.53.v20231009

- netty: https://github.com/netty/netty/commit/58f75f665aa81a8cbcf6ffa74820042a285c5e61

- nghttp2: https://github.com/nghttp2/nghttp2/pull/1961 https://github.com/nghttp2/nghttp2/releases/tag/v1.57.0

- nginx: https://www.nginx.com/blog/http-2-rapid-reset-attack-impacting-f5-nginx-products/ https://mailman.nginx.org/pipermail/nginx-devel/2023-October/S36Q5HBXR7CAIMPLLPRSSSYR4PCMWILK.html

- nodejs: https://github.com/nodejs/node/pull/50121

- proxygen: https://github.com/facebook/proxygen/pull/466

- swift-nio-http2: https://forums.swift.org/t/swift-nio-http2-security-update-cve-2023-44487-http-2-dos/67764

- tomcat: https://tomcat.apache.org/security-11.html#FixedinApacheTomcat11.0.0-M12 https://tomcat.apache.org/security-10.html#FixedinApacheTomcat10.1.14 https://tomcat.apache.org/security-9.html#FixedinApacheTomcat9.0.81 https://tomcat.apache.org/security-8.html#FixedinApacheTomcat8.5.94

-- -Alan Coopersmith- alan.coopersmith () oracle com Oracle Solaris Engineering - https://blogs.oracle.com/solaris

A flaw was found in the Jetty-server package. This flaw allows an attacker to send invalid requests, causing a denial of service in the Jetty Server.

A vulnerability was found in keycloak, where on using lower case HTTP headers (via cURL) we can bypass our Gatekeeper. Lower case headers are also accepted by some webservers (e.g. Jetty). This means there is no protection when we put a Gatekeeper in front of a Jetty server and use lowercase headers.

References: https://issues.jboss.org/browse/KEYCLOAK-14090

Eclipse Jetty is vulnerable to cross-site scripting, caused by improper validation of user-supplied input. A remote attacker could exploit this vulnerability using the error messages to inject malicious script into a Web page which would be executed in a victim's Web browser within the security context of the hosting Web site, once the page is viewed. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.

JSP Dump and Session Dump Servlet XSS in jetty before 6.1.22.

Dump Servlet information leak in jetty before 6.1.22.

WebApp JSP Snoop page XSS in jetty though 6.1.21.

Cookie Dump Servlet stored XSS vulnerability in jetty though 6.1.20.

Eclipse Jetty could allow a remote attacker to obtain sensitive information, caused by a flaw when configured for showing a listing of directory contents. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to obtain sensitive information.

Eclipse Jetty is vulnerable to a denial of service, caused by the additional CPU and memory allocations required to handle changed settings. By sending either large SETTINGs frames container containing many settings, or many small SETTINGs frames, a remote attacker could exploit this vulnerability to cause a denial of service.

Eclipse Jetty could allow a remote attacker to obtain sensitive information. An attacker could send a specially-crafted URL request to the java.nio.file.InvalidPathException function using an invalid parameter to cause an error message to be returned containing the full installation path. An attacker could use this information to launch further attacks against the affected system.

Eclipse Jetty is vulnerable to HTTP request smuggling, caused by a flaw in the HTTP/1.x Parser. By sending a specially-crafted request, an attacker could exploit this vulnerability to poison the web cache, bypass web application firewall protection, and conduct XSS attacks.

Eclipse Jetty could allow a remote attacker to hijack a user's session, caused by a flaw in the FileSessionDataStore. An attacker could exploit this vulnerability to gain access to another user's session.

The path normalization mechanism in PathResource class in Eclipse Jetty 9.3.x before 9.3.9 on Windows allows remote attackers to bypass protected resource restrictions and other security constraints via a URL with certain escaped characters, related to backslashes.

The exception handling code in Eclipse Jetty before 9.2.9.v20150224 allows remote attackers to obtain sensitive information from process memory via illegal characters in an HTTP header, aka JetLeak.

End of life: 12/7/2020, End of support: 12/7/2020, Latest version: 9.3.30.v20211001

End of life: 12/7/2020, End of support: 12/7/2020, Latest version: 9.3.30.v20211001

End of life: 3/8/2018, End of support: 3/8/2018, Latest version: 9.2.30.v20200428

End of life: 3/8/2018, End of support: 3/8/2018, Latest version: 9.2.30.v20200428

End of life: 12/31/2014, End of support: 12/31/2014, Latest version: 9.1.6.v20160112

End of life: 12/31/2014, End of support: 12/31/2014, Latest version: 9.1.6.v20160112

End of life: 12/31/2013, End of support: 12/31/2013, Latest version: 9.0.7.v20131107

End of life: 12/31/2013, End of support: 12/31/2013, Latest version: 9.0.7.v20131107

Jetty 8.1.0.RC2 and earlier computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.

End of life: 12/31/2014, End of support: 12/31/2014, Latest version: 8.2.0.v20160908