The first advisory "Fine Grained Auditing issue in Oracle 9i / 10g". The issue is where a SELECT is performed as SYS. There are two problems, the first is that the select statement as SYS is not audited and the second is that subsequent selects by any other user are also not audited. Alex goes on to show example code to demonstrate the issue. He also gives two workarounds, the first, do not run SQL on FGA objects as SYS and also flush the shared pool to activate auditing again. The second could give disadvantages to performance on the database.
The second advisory is "DBMS_SCHEDULER 10g SELECT user issue in Oracle 10g". This issue is that a user with CREATE JOB can run any job and after he has done so he has had the session_user switched to SYS. Alex gives example exploit code based on that available from metalink.
The big question is why were security advisories not made available from Oracle for these issues when they were fixed?