Dokku: community verdicts

Dokku is a docker-powered PaaS. Prior to 0.38.7, the cron plugin utilizes commands in the app.json file to manage system cron running as the Dokku user. An app.json cron command utilizing special shell characters - including, but not limited to, > or ; - can break out of the Docker container and execute commands on the host as the Dokku user. This vulnerability is fixed in 0.38.7.

Dokku is a docker-powered PaaS. Prior to 0.38.2, the openresty-vhosts plugin copies files from an app's openresty/http-includes/ git repository directory to the host and then interpolates their filenames, unescaped, into a single-quoted shell string that is later parsed by eval. A filename containing a single quote breaks the quoting and allows command substitution to execute arbitrary commands on the host as the dokku user during the app's next deploy. This vulnerability is fixed in 0.38.2.

Dokku is a docker-powered PaaS. Prior to 0.38.2, the app name validation regex (^[a-z0-9][^/:_A-Z]*$) permits shell metacharacters. When an authenticated user pushes to a git remote with a crafted app name, the name is embedded unquoted into a bash pre-receive hook script via an unquoted heredoc (<<EOF instead of <<'EOF') in fn-git-create-hook() at plugins/git/internal-functions:378. On git push, bash interprets the semicolon as a command separator, executing arbitrary commands as the dokku user. This vulnerability is fixed in 0.38.2.

Dokku is a docker-powered PaaS. Prior to 0.38.2, the git:from-archive and certs:add commands extract user-supplied tar/zip archives into temporary directories without sanitizing member paths or preventing symlink traversal. GNU tar creates symlinks during extraction and follows them for subsequent entries, allowing an attacker to write arbitrary files anywhere writable by the dokku user — including overwriting ~/.ssh/authorized_keys to gain unrestricted shell access. This vulnerability is fixed in 0.38.2.

Dokku is a docker-powered PaaS. Prior to 0.38.2, the git:auth command creates $DOKKU_ROOT/.netrc using bash's touch command, which applies the default umask of 0644. This pre-creation defeats the netrc binary's built-in 0600 permission setting, leaving git credentials readable by any local user who can traverse the dokku home directory. This vulnerability is fixed in 0.38.2.