Title: ZOHO ManageEngine ADSelfService Plus Administrative Access
Release date: 11/10/2011
Last update: 11/10/2011
Credits: Roberto Paleari, Emaze Networks S.p.A.
Class: Authentication issue, Administrative access
- ADSelfService Plus 4.5 Build 4521
Previous versions are probably also vulnerable, but they were not checked.
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:
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:
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.
- 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(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 firstname.lastname@example.org to have more information about ipLegion.
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