Describe CVE-2018-12939.
What is CVE-2018-12939?
A directory traversal flaw in SeedDMS (formerly LetoDMS and MyDMS) before 5.1.8 allows an authenticated attacker to write to (or potentially delete) arbitrary files via a .. (dot dot) in the "op/op.UploadChunks.php" "qquuid" parameter.  NOTE: this can be leveraged to execute arbitrary code by using CVE-2018-12940..