OCIPasswordChange API leaks information of password hash (CVE-2012-0511)

Type securityvulns
Reporter Securityvulns
Modified 2012-04-22T00:00:00



AppSecInc Team SHATTER Security Advisory

OCIPasswordChange API leaks information of password hash.

Risk Level: High

Affected versions: Oracle Database Server version 10gR1, 10gR2 ( and previous patchsets) and 11gR1 ( and previous patchsets)

Remote exploitable: Yes (No authentication is required)

Credits: This vulnerability was discovered and researched by Esteban Martinez Fayo of Application Security Inc.

Details: Oracle Database provides OCIPasswordChange API to change user passwords. This API can be used while a user is logged on as well as before the authentication process is completed, this is because it can be used for accounts that have the password expired so that the user is able to change an expired password for a new one. It was observed that for locked accounts this API leaks information about the correct user password hash by giving different responses, depending on whether the decryption of the new password (AUTH_NEW_PASSWORD field), performed by the server, is successful or not. This information can be used to perform an off-line brute force attack to guess the correct password. Internal proof-of-concept tool demonstrated that it is possible to try millions of passwords per second, making it possible to crack passwords that are less than 9 characters length in a few hours. Note that to perform this attack the account must be locked. An attacker can lock an account by reaching the maximum failed login attempts limit (by default 10). The attacker will be able to log in as the user once the account is unlocked.

Impact: Remote unauthenticated attackers can perform off-line unlimited password guesses on locked database accounts.

Vendor Status: Vendor was contacted and a patch was released.

Workaround: Implement a strong password policy. Use some kind of external authentication (like network or directory service based) instead of native database authentication.

Fix: Apply Oracle Critical Patch Update April 2012 available at Oracle Support.

CVE: CVE-2012-0511

Links: http://www.oracle.com/technetwork/topics/security/cpuapr2012-366314.html https://www.teamshatter.com/?p=3434

Timeline: Vendor Notification - 12/08/2011 Vendor Response - 12/15/2011 Fix - 4/17/2012 Public Disclosure - 4/19/2012

Copyright (c) 2012 Application Security, Inc. http://www.appsecinc.com About Application Security, Inc.

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Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (MingW32) - WinPT 1.4.3 Charset: UTF-8

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