Jetty is a java based web server and servlet engine. In affected versions servlets with multipart support (e.g. annotated with @MultipartConfig) that call HttpServletRequest.getParameter() or HttpServletRequest.getParts() may cause OutOfMemoryError when the client sends a multipart request with a part that has a name but no filename and very large content. This happens even with the default settings of fileSizeThreshold=0 which should stream the whole part content to disk. An attacker client may send a large multipart request and cause the server to throw OutOfMemoryError. However, the server may be able to recover after the OutOfMemoryError and continue its service – although it may take some time. This issue has been patched in versions 9.4.51, 10.0.14, and 11.0.14. Users are advised to upgrade. Users unable to upgrade may set the multipart parameter maxRequestSize which must be set to a non-negative value, so the whole multipart content is limited (although still read into memory).
The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Jetty | Eclipse | * | 9.4.51 (excluding) |
| Jetty | Eclipse | 10.0.0 (including) | 10.0.14 (excluding) |
| Jetty | Eclipse | 11.0.0 (including) | 11.0.14 (excluding) |
Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:
Resource exhaustion problems are often result due to an incorrect implementation of the following situations:
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.