A flaw was found in rsync. When using the `--safe-links` option, the rsync client fails to properly verify if a symbolic link destination sent from the server contains another symbolic link within it. This results in a path traversal vulnerability, which may lead to arbitrary file write outside the desired directory.
An issue was discovered in rsync before 3.2.5 that allows malicious remote servers to write arbitrary files inside the directories of connecting peers. The server chooses which files/directories are sent to the client. However, the rsync client performs insufficient validation of file names. A malicious rsync server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the rsync client target directory and subdirectories (for example, overwrite the .ssh/authorized_keys file).
A flaw was found in rsync in versions since 3.2.0pre1. Rsync improperly validates certificate with host mismatch vulnerability. A remote, unauthenticated attacker could exploit the flaw by performing a man-in-the-middle attack using a valid certificate for another hostname which could compromise confidentiality and integrity of data transmitted using rsync-ssl. The highest threat from this vulnerability is to data confidentiality and integrity. This flaw affects rsync versions before 3.2.4.