CVE-2020-27223

In Eclipse Jetty 9.4.6.v20170531 to 9.4.36.v20210114 (inclusive), 10.0.0, and 11.0.0 when Jetty handles a request containing multiple Accept headers with a large number of “quality” (i.e. q) parameters, the server may enter a denial of service (DoS) state due to high CPU usage processing those quality values, resulting in minutes of CPU time exhausted processing those quality values.

In Eclipse Jetty 9.4.6.v20170531 to 9.4.36.v20210114 (inclusive), 10.0.0, and 11.0.0 when Jetty handles a request containing multiple Accept headers with a large number of “quality” (i.e. q) parameters, the server may enter a denial of service (DoS) state due to high CPU usage processing those quality values, resulting in minutes of CPU time exhausted processing those quality values.

### Impact When Jetty handles a request containing request headers with a large number of “quality” (i.e. q) parameters (such as what are seen on the `Accept`, `Accept-Encoding`, and `Accept-Language` request headers), the server may enter a denial of service (DoS) state due to high CPU usage while sorting the list of values based on their quality values. A single request can easily consume minutes of CPU time before it is even dispatched to the application. The only features within Jetty that can trigger this behavior are: - Default Error Handling - the `Accept` request header with the `QuotedQualityCSV` is used to determine what kind of content to send back to the client (html, text, json, xml, etc) - `StatisticsServlet` - uses the `Accept` request header with the `QuotedQualityCSV` to determine what kind of content to send back to the client (xml, json, text, html, etc) - `HttpServletRequest.getLocale()` - uses the `Accept-Language` request header with the `QuotedQualityCSV` to determine which “preferred” language is returned on this call. - `HttpservletRequest.getLocales()` - is similar to the above, but returns an ordered list of locales based on the quality values on the `Accept-Language` request header. - `DefaultServlet` - uses the `Accept-Encoding` request header with the `QuotedQualityCSV` to determine which kind of pre-compressed content should be sent back for static content (content that is not matched against a url-pattern in your web app) ### Versions `QuotedQualityCSV` was introduced to Jetty 9.3.9.v20160517 and the bug that introduced the vulnerability was in 9.4.6.v20170531. Currently, known vulnerable versions include: - 9.4.6.v20170531 thru to 9.4.36.v20210114 - 10.0.0 - 11.0.0 ### Workarounds Quality ordered values are used infrequently by jetty so they can be avoided by: * Do not use the default error page/handler. * Do not deploy the `StatisticsServlet` exposed to the network * Do not call `getLocale` API * Do not enable precompressed static content in the `DefaultServlet` ### Patches All patches are available for download from the Eclipse Jetty website at [https://www.eclipse.org/jetty/download.php](https://www.eclipse.org/jetty/download.php) - 9.4.37.v20210219 and greater - 10.0.1 and greater - 11.0.1 and greater

### Impact When Jetty handles a request containing request headers with a large number of “quality” (i.e. q) parameters (such as what are seen on the `Accept`, `Accept-Encoding`, and `Accept-Language` request headers), the server may enter a denial of service (DoS) state due to high CPU usage while sorting the list of values based on their quality values. A single request can easily consume minutes of CPU time before it is even dispatched to the application. The only features within Jetty that can trigger this behavior are: - Default Error Handling - the `Accept` request header with the `QuotedQualityCSV` is used to determine what kind of content to send back to the client (html, text, json, xml, etc) - `StatisticsServlet` - uses the `Accept` request header with the `QuotedQualityCSV` to determine what kind of content to send back to the client (xml, json, text, html, etc) - `HttpServletRequest.getLocale()` - uses the `Accept-Language` request header with the `QuotedQualityCSV` to determine which “preferred” language is returned on this call. - `HttpservletRequest.getLocales()` - is similar to the above, but returns an ordered list of locales based on the quality values on the `Accept-Language` request header. - `DefaultServlet` - uses the `Accept-Encoding` request header with the `QuotedQualityCSV` to determine which kind of pre-compressed content should be sent back for static content (content that is not matched against a url-pattern in your web app) ### Versions `QuotedQualityCSV` was introduced to Jetty 9.3.9.v20160517 and the bug that introduced the vulnerability was in 9.4.6.v20170531. Currently, known vulnerable versions include: - 9.4.6.v20170531 thru to 9.4.36.v20210114 - 10.0.0 - 11.0.0 ### Workarounds Quality ordered values are used infrequently by jetty so they can be avoided by: * Do not use the default error page/handler. * Do not deploy the `StatisticsServlet` exposed to the network * Do not call `getLocale` API * Do not enable precompressed static content in the `DefaultServlet` ### Patches All patches are available for download from the Eclipse Jetty website at [https://www.eclipse.org/jetty/download.php](https://www.eclipse.org/jetty/download.php) - 9.4.37.v20210219 and greater - 10.0.1 and greater - 11.0.1 and greater

En Eclipse Jetty versiones 9.4.6.v20170531 hasta 9.4.36.v20210114 (inclusive), versiones 10.0.0 y 11.0.0, cuando Jetty maneja una petición que contiene múltiples encabezados Accept con una gran cantidad de parámetros “quality” (es decir, q), el servidor puede entrar en un estado de denegación de servicio (DoS) debido al alto uso de CPU procesando esos valores de calidad, resultando en minutos de tiempo de CPU agotados procesando esos valores de calidad