View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2017-7660 medium priority: Ubuntu including 1 source packages (lucene-solr), 5 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): not-affected 4, needs-triage 1.
Apache Solr uses a PKI based mechanism to secure inter-node communication when security is enabled. It is possible to create a specially crafted node name that does not exist as part of the cluster and point it to a malicious node. This can trick the nodes in cluster to believe that the malicious node is a member of the cluster. So, if Solr users have enabled BasicAuth authentication mechanism using the BasicAuthPlugin or if the user has implemented a custom Authentication plugin, which does not implement either "HttpClientInterceptorPlugin" or "HttpClientBuilderPlugin", his/her servers are vulnerable to this attack. Users who only use SSL without basic authentication or those who use Kerberos are not affected.