An XML External Entity (XXE) vulnerability exists in the Ambari/Oozie
project, allowing an attacker to inject malicious XML entities. This
vulnerability occurs due to insecure parsing of XML input using the
DocumentBuilderFactory
class without disabling external entity
resolution. An attacker can exploit this vulnerability to read arbitrary
files on the server or perform server-side request forgery (SSRF)
attacks. The issue has been fixed in both Ambari 2.7.9 and the trunk
branch.