Werkzeug is a comprehensive WSGI web application library. If an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Werkzeug | Palletsprojects | * | 2.3.8 (excluding) |
| Werkzeug | Palletsprojects | 3.0.0 (including) | 3.0.0 (including) |
| Ironic content for Red Hat OpenShift Container Platform 4.12 | RedHat | python-werkzeug-0:2.0.3-5.el9 | * |
| Ironic content for Red Hat OpenShift Container Platform 4.13 | RedHat | python-werkzeug-0:2.0.3-5.el9 | * |
| Red Hat Ceph Storage 8.1 | RedHat | ceph-2:19.2.1-222.el9cp | * |
| Red Hat Ceph Storage 8.1 | RedHat | cephadm-ansible-1:4.1.4-1.el9cp | * |
| Red Hat Ceph Storage 8.1 | RedHat | oath-toolkit-0:2.6.12-1.el9cp | * |
| Red Hat OpenShift Container Platform 4.14 | RedHat | python-werkzeug-0:2.2.3-2.el9 | * |
| Red Hat OpenStack Platform 17.1 for RHEL 8 | RedHat | python-werkzeug-0:2.0.1-8.el8ost | * |
| Red Hat OpenStack Platform 17.1 for RHEL 9 | RedHat | python-werkzeug-0:2.0.1-6.el9ost | * |
| Werkzeug | Ubuntu | bionic | * |
| Werkzeug | Ubuntu | trusty | * |
| Werkzeug | Ubuntu | xenial | * |
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.