Headline
CVE-2021-21694: Jenkins Security Advisory 2021-11-04
FilePath#toURI, FilePath#hasSymlink, FilePath#absolutize, FilePath#isDescendant, and FilePath#get*DiskSpace do not check any permissions in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.
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Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create parent directories in FilePath#mkdirs.
FilePath#renameTo and FilePath#moveAllChildrenTo in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier only check 'read' agent-to-controller access permission on the source path, instead of 'delete'.
Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create symbolic links when unarchiving a symbolic link in FilePath#untar.
FilePath#unzip and FilePath#untar were not subject to any agent-to-controller access control in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.
When creating temporary files, agent-to-controller access to create those files is only checked after they've been created in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.
FilePath#listFiles lists files outside directories that agents are allowed to access when following symbolic links in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.
Jenkins 2.318 and earlier, LTS 2.303.2 and earlier allows any agent to read and write the contents of any build directory stored in Jenkins with very few restrictions.
Creating symbolic links is possible without the 'symlink' agent-to-controller access control permission in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.