Blue Ocean allows the creation of GitHub organization folders that are set up to scan a GitHub organization for repositories and branches containing a Jenkinsfile, and create corresponding pipelines in Jenkins. Its SCM content REST API supports the pipeline creation and editing feature in Blue Ocean. The SCM content REST API did not check the current user's authentication or credentials. If the GitHub organization folder was created via Blue Ocean, it retained a reference to its creator's GitHub credentials. This allowed users with read access to the GitHub organization folder to create arbitrary commits in the repositories inside the GitHub organization corresponding to the GitHub organization folder with the GitHub credentials of the creator of the organization folder. Additionally, users with read access to the GitHub organization folder could read arbitrary file contents from the repositories inside the GitHub organization corresponding to the GitHub organization folder if the branch contained a Jenkinsfile (which could be created using the other part of this vulnerability), and they could provide the organization folder name, repository name, branch name, and file name.
Git Plugin connects to a user-specified Git repository as part of form validation. An attacker with no direct access to Jenkins but able to guess at a username/password credentials ID could trick a developer with job configuration permissions into following a link with a maliciously crafted Jenkins URL which would result in the Jenkins Git client sending the username and password to an attacker-controlled server.
The optional Run/Artifacts permission can be enabled by setting a Java system property.
Blue Ocean did not check this permission before providing access to archived artifacts, Item/Read permission was sufficient.
Blue Ocean now correctly checks the Run/Artifacts permission if it’s enabled before providing access to artifacts.