An issue was discovered in Cleo LexiCom 5.5.0.0. Within the AS2 message, the sender can specify a filename. This filename can include path-traversal characters, allowing the file to be written to an arbitrary location on disk.
https://www.cleo.com/cleo-lexicom
https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0011.md