Information disclosure

A vulnerability exists in the HCI IEC 60870-5-104 that affects the RTU500 series product versions listed below.
Incomplete or wrong received APDU frame layout may
cause blocking on link layer. Error reason was an endless blocking when reading incoming frames on link layer
with wrong length information of APDU or delayed reception
of data octets.

Only communication link of affected HCI IEC 60870-5-104
is blocked. If attack sequence stops the communication to
the previously attacked link gets normal again.