The check_secret function in authenticate.c in rsync 3.1.0 and earlier allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a user name which does not exist in the secrets file.

rsync 3.x before 3.0.8, when certain recursion, deletion, and ownership options are used, allows remote rsync servers to cause a denial of service (heap memory corruption and application crash) or possibly execute arbitrary code via malformed data.

Buffer overflow in rsync 2.6.9 to 3.0.1, with extended attribute (xattr) support enabled, might allow remote attackers to execute arbitrary code via unknown vectors.