Package Instance

Incorrect permission checks in Jenkins Matrix Authorization Strategy Plugin may allow accessing some items
Items (like jobs) can be organized hierarchically in Jenkins, using the Folders Plugin or something similar. An item is expected to be accessible only if all its ancestors are accessible as well.

Matrix Authorization Strategy Plugin 2.6.5 and earlier does not correctly perform permission checks to determine whether an item should be accessible.

This allows attackers with Item/Read permission on nested items to access them, even if they lack Item/Read permission for parent folders.\n\nMatrix Authorization Strategy Plugin 2.6.6 requires Item/Read permission on parent items to grant Item/Read permission on an individual item.

As a workaround in older releases, do not grant permissions on individual items to users who do not have access to parent items.

In case of problems, the [Java system property](https://www.jenkins.io/doc/book/managing/system-properties/) `hudson.security.AuthorizationMatrixProperty.checkParentPermissions` can be set to false, completely disabling this fix.

Lack of type validation in agent related REST API in Jenkins
Jenkins 2.286 and earlier, LTS 2.277.1 and earlier does not validate the type of object created after loading the data submitted to the `config.xml` REST API endpoint of a node.

This allows attackers with Computer/Configure permission to replace a node with one of a different type.

Jenkins 2.287, LTS 2.277.2 validates the type of object created and rejects objects of unexpected types.

View name validation bypass in Jenkins
Jenkins 2.286 and earlier, LTS 2.277.1 and earlier does not properly check that a newly created view has an allowed name. When a form to create a view is submitted, the name is included twice in the submission. One instance is validated, but the other instance is used to create the value.

This allows attackers with View/Create permission to create views with invalid or already-used names.

Jenkins 2.287, LTS 2.277.2 uses the same submitted value for validation and view creation.