Cisco ASA firewalls don't log, by default, the username used in a failed administrator login. Instead, the login is masked out using "*" characters:
%ASA-6-113005: AAA user authentication Rejected : reason = AAA failure : server = 10.1.1.1 : user = ***** : user IP = 192.168.0.10
The rationale is that users sometimes enter their password instead of the username, and the password will then end up in logs. As we're using two-factor authentication for admin logins, that doesn't apply to us.
That behaviour was actually tracked as a bug in Cisco's bug database (cache), and while the article mentions that a command was introduced to change this behaviour, the command itself isn't mentioned.
After some fiddling on the ASA command line I found this statement:
no logging hide username
The corresponding button in the ASDM GUI is in Device Management -> Logging -> Syslog Setup: "Hide username if its validity cannot be determined"
%ASA-6-113005: AAA user authentication Rejected : reason = AAA failure : server = 10.1.1.1 : user = ***** : user IP = 192.168.0.10
The rationale is that users sometimes enter their password instead of the username, and the password will then end up in logs. As we're using two-factor authentication for admin logins, that doesn't apply to us.
That behaviour was actually tracked as a bug in Cisco's bug database (cache), and while the article mentions that a command was introduced to change this behaviour, the command itself isn't mentioned.
After some fiddling on the ASA command line I found this statement:
no logging hide username
The corresponding button in the ASDM GUI is in Device Management -> Logging -> Syslog Setup: "Hide username if its validity cannot be determined"