Composer is a dependency manager for PHP. On the 2.x branch prior to versions 2.2.24 and 2.7.7, the status, reinstall and remove commands with packages installed from source via git containing specially crafted branch names in the repository can be used to execute code. Patches for this issue are available in version 2.2.24 for 2.2 LTS or 2.7.7 for mainline. As a workaround, avoid installing dependencies via git by using --prefer-dist or the preferred-install: dist config setting.