remove mention of specific attacks

Author: gregsdennis

specs/jsonschema-core.md

@@ -1994,8 +1994,7 @@ When encountering an IRI that also represents a valid file system or network
 location, implementations are discouraged from automatically making an operation to
 access that location. Schema authors should take care when configuring
 implementations to operate over a file system or network as this could expose
-the host system to various security vulnerabilities, such as man-in-the-middle
-attacks or data leaks.
+the host system.
 
 ## IANA Considerations