We have identified that for DynaFile clients that transmit synchronization or document data via SFTP and that are using older Java based clients, that the Java client is not conforming to the SSH RFC (https://datatracker.ietf.org/doc/html/rfc4253#section-4.2) by not including a CR symbol in the client identification string SSH-2.0-JSCH-0.1.54, which is mandatory per the RFC. A recent security update to our SFTP systems was enforcing compliance to this RFC. We have seen this issue appear as of 1/22 with a very limited number of clients that use SAP and Oracle for data transmission.
We will be applying a hot-fix our SFTP systems at 9:00 PM MST on 1/25 which will remove enforcement of this RFC requirement and which should allow legacy Java clients to continue to connect to our SFTP servers. Clients that experienced SFTP transmission issues since 1/22 should re-attempt to connect on 1/26 and to republish any data that was unable to be delivered.
As this hot-fix will not stay permanent as we continue to update our systems in the future, we strongly recommend that clients using these older Java platforms for SFTP transmission adapt their infrastructure to be compliant with the RFC and use clients running the latest version of the JSch library (see: https://github.com/mwiede/jsch/releases/tag/jsch-0.1.69). Versions from October 2021 and later have the fix for RFC compliance.