Oracle Database Server version 11gR1, 11gR2
Yes (No authentication to Database Server is needed)
This vulnerability was discovered and researched by Esteban Martinez Fayo of Application Security Inc.
There is a flaw in the way that Authentication Session Keys are generated and protected by Oracle Database Server during the authentication process. It is possible to use this flaw to perform unlimited password guesses (cracking) of any user password in a similar way as if the password hash would be available.
All users that are authenticated by the database using logon protocol version 11 are affected by this vulnerability. This includes all users created with the “IDENTIFIED BY” clause, including the SYS user.
The attack can be performed remotely without the need of a valid username and password. The attacker just needs to know the SID of the database and the name of a valid user. The attack can be done with just a few network packets and without leaving any trace in native auditing facilities.
Remote unauthenticated attackers can perform offline bruteforce on users passwords, testing millions of passwords per second.
Vendor was contacted and a patch was released.
Some possible workarounds:
1) Use strong user passwords. A strong password will make password guessing more difficult (or impossible) to solve in reasonable time.
2) Use external authentication. Only users that are authenticated by the database are affected by this vulnerability. Users that are authentication by external means are not affected; this includes users authenticated by the Operating System and the Network (SSL or third-parties like Kerberos).
3) Disable protocol version 11 and use version 10 or lower instead. To do this, set initialization parameter SEC_CASE_SENSITIVE_LOGON to FALSE.
See our detailed post about this vulnerability for more information about the workarounds.
Apply Oracle Critical Patch Update October 2012 available at Oracle Support.
Vendor Notification – 4/21/2010
Vendor Response – 4/26/2010
Fix – 10/16/2012
Public Disclosure – 11/12/2012