CVE-2020-26277: Improper Link Resolution Before File Access ('Link Following')

DBdeployer is a tool that deploys MySQL database servers easily. In DBdeployer, users unpacking a tarball may use a maliciously packaged tarball that contains symlinks to files external to the target. In such scenario, an attacker could induce dbdeployer to write into a system file, thus altering the computer defenses. For the attack to succeed, the following factors need to contribute: 1) The user is logged in as root. While dbdeployer is usable as root, it was designed to run as unprivileged user. 2) The user has taken a tarball from a non secure source, without testing the checksum. When the tarball is retrieved through dbdeployer, the checksum is compared before attempting to unpack.