Four flaws were reported in Apache Ambari:

CVE-2015-5210: Unvalidated Redirects and Forwards using targetURI parameter can enable phishing exploits
Versions Affected: 1.7.0 to 2.1.1
Versions Fixed: 2.1.2
Description: A redirect to an untrusted server is possible via unvalidated input that specifies a redirect URL upon 
successful login.

CVE-2015-3186: Apache Ambari XSS vulnerability
Versions Affected: 1.7.0 to 2.0.2
Versions Fixed: 2.1.0
Description: Ambari allows authenticated cluster operator users to specify arbitrary text as a note when saving 
configuration changes. This note field is rendered as is (unescaped HTML).  This exposes opportunities for XSS.

CVE-2015-3270: A non-administrative user can escalate themselves to have administrative privileges remotely
Versions Affected: 1.7.0, 2.0.0, 2.0.1, 2.1.0
Versions Fixed: 2.0.2, 2.1.1
Description: An authenticated user can remotely escalate his/her permissions to administrative level. This can escalate 
their privileges for access through the API as well from the UI.

CVE-2015-1775: Apache Ambari Server Side Request Forgery vulnerability
Versions Affected: 1.5.0 to 2.0.2
Versions Fixed: 2.1.0
Description: Ambari exposes a proxy endpoint through “api/v1/proxy” that can be used make REST calls to arbitrary 
host:port that are accessible from the Ambari server host. Ability to make these calls is limited to Ambari 
authenticated users only. In addition, an user need to be Ambari admin user to make the REST calls using METHODs other 
than GET (non-admin users can only call GET). This ability to call allows malicious users to perform port scans and/or 
access unsecured services visible to the Ambari Server host through the proxy endpoint. In addition Ambari provides an 
utility to handle such proxy calls that are used by View instances hosted by Ambari

External References:

https://cwiki.apache.org/confluence/display/AMBARI/Ambari+Vulnerabilities