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.