Format string vulnerability in a logging function as used by various SFTP servers, including (1) AttachmateWRQ Reflection for Secure IT UNIX Server before 6.0.0.9, (2) Reflection for Secure IT Windows Server before 6.0 build 38, (3) F-Secure SSH Server for Windows before 5.3 build 35, (4) F-Secure SSH Server for UNIX 3.0 through 5.0.8, (5) SSH Tectia Server 4.3.6 and earlier and 4.4.0, and (6) SSH Shell Server 3.2.9 and earlier, allows remote authenticated users to execute arbitrary commands via unspecified vectors, involving crafted filenames and the stat command.

WRQ Reflection for Secure IT Windows Server 6.0 (formerly known as F-Secure SSH server) processes access and deny lists in a case-sensitive manner, when previous versions were case-insensitive, which might allow remote attackers to bypass intended restrictions and login to accounts that should be denied.

WRQ Reflection for Secure IT Windows Server 6.0 (formerly known as F-Secure SSH server) does not properly handle when the Windows Administrator or Guest accounts are renamed after SSH key authentication has been configured, which allows remote attackers to use the original names during login.