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PURPOSE

This troubleshooting guide is aimed at providing information on how to trace suspect logins that have failed with ora-1017, logon denied during database authentication. Note that a malicious origin is in most cases not the cause of an unsuccessful login. It can be simply a typo in the username or password, a cron job with an invalid password in it or even an Oracle client program that was badly configured (for example see referenced note 267401.1). Anyway these unsuccessful connect attempts can be a nuisance, especially when a password management policy is in place that has a limit on failed_login_attempts and cause the ora-28000 "the account is locked" error.

TROUBLESHOOTING STEPS

Check DBA_USERS

If the ACCOUNT_STATUS for the user is LOCKED, this means the account was locked by a DBA doingALTER USER &username ACCOUNT LOCK;if the ACCOUNT_STATUS is LOCKED(TIMED) this means it was locked because of exceeding the number of allowed FAILED_LOGIN_ATTEMPTS, this is true even if the PASSWORD_LOCK_TIME is set to unlimited. An account will never get locked due to password expiration. Before the account is actually locked you can inspect the number of failed login attempts so far by checking the USER$.LCOUNT column:

Audit unsuccessful logins

At first establish standard auditing by setting audit_trail = db and issue:

AUDIT SESSION WHENEVER NOT SUCCESSFUL;

The audit records for unsuccessful logon attempts from 'last week' can be found as follows:

Comment: The USERHOST column is only populated with theClient Host machine nameas of 10G, in earlier versions this was theNumeric instance ID for the Oracle instance from which the user is accessing the databasein a RAC environment.

Optionally select more columns, these may however not provide you with relevant information, your reason for checking this note may be that you found some entries here and need more information. Try to correlate the DBA_USERS.LOCK_DATE with the time scripts or batch jobs are being run.

Set an event in the "init.ora" parameter file

Set the following event in your parameter file to dump a trace file whenever an ORA-1017 is generated:

Alternatively you can issue the following command as a privileged user, this will only affect new processes so may not work in a Shared Server environment:

This will produce a trace file in user_dump_dest whenever someone attempts an invalid username / password , since the trace is requested at level 10, it will include a section labeled PROCESS STATE that includes trace information like:

In this case it was an sqlplus client started by OS user 'userx' that started the client session. The section Call Stack Trace may aid support in further diagnosing the issue. Tip: If the OS user or program is 'oracle' the connection may originate from a Database Link.

Use a trigger to capture additional information

The following trigger code can be used to gather additional information about unsuccessful login attempts, it is recommended to integrate this code into an existing trigger if you already have a trigger for this triggering event instead of having more triggers on the same event, note this is just an example providing some essential information, it can be changed or modified at will, for example you may prefer to log the entries in a table instead of the alert.log file, it appears this trigger fires even if the session is not authenticated, please keep the trigger code as simply as possible as to minimize the performance impact.

Some sample output from the alert.log looks like:

Fri May 20 10:00:50 2011 Fri May 20 10:00:50 2011 logon denied IP = localhost pid = **** os user = oracle client id = with program= sqlplus@<host name> (TNS V1-V3) module=sqlplus@<host name> (TNS V1-V3) action= 

More attributes may be found in note 120797.1 , however please consider when this trigger fires on an unsuccessful logon attempt, not all session specific information may be available as it would be for an authenticated session.

Use SQLNET Tracing to gather detailed information

An sqlnet trace can provide you with even more details about the connection attempt, use this only if the above does not provide you with enough information, since it will be hard to find what you are looking for if you enable sqlnet tracing, to enable it create or edit the server side sqlnet.ora file and put in the following parameters:

# server side sqlnet trace parameters

trace_level_server = 16

trace_file_server=server

trace_directory_server = <any directory on a volume with enough freespace>

As a last resort you may want to set your hopes on a packet sniffer on the network or operating system level, the use of such tools however is beyond the scope of this article, you may want to consult your local network administrator about this possibility.

REFERENCES