In Suricata before 6.0.13 (when there is an adversary who controls an external source of rules), a dataset filename, that comes from a rule, may trigger absolute or relative directory traversal, and lead to write access to a local filesystem. This is addressed in 6.0.13 by requiring allow-absolute-filenames and allow-write (in the datasets rules configuration section) if an installation requires traversal/writing in this situation.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.