Eclipse Jetty is vulnerable to a denial of service, caused by an error when handling a request containing multiple Accept headers with a large number of quality parameters. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to exhaust minutes of CPU time.

Eclipse Jetty is vulnerable to cross-site scripting, caused by improper validation of user-supplied input by the DefaultServlet and ResourceHandler. A remote attacker could exploit this vulnerability using a specially-crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.

In Eclipse Jetty version 7.x, 8.x, 9.2.27 and older, 9.3.26 and older, and 9.4.16 and older, the server running on any OS and Jetty version combination will reveal the configured fully qualified directory base resource location on the output of the 404 error for not finding a Context that matches the requested path. The default server behavior on jetty-distribution and jetty-home will include at the end of the Handler tree a DefaultHandler, which is responsible for reporting this 404 error, it presents the various configured contexts as HTML for users to click through to. This produced HTML includes output that contains the configured fully qualified directory base resource location for each context.