CVE-2024-52797: Searching Opencast may cause a denial of service

First noticed in Opencast 13 and 14, Opencast’s Elasticsearch integration may generate syntactically invalid Elasticsearch queries in relation to previously acceptable search queries. From Opencast version 11.4 and newer, Elasticsearch queries are retried a configurable number of times in the case of error to handle temporary losses of connection to Elasticsearch. These invalid queries would fail, causing the retry mechanism to begin requerying with the same syntactically invalid query immediately, in an infinite loop. This causes a massive increase in log size which can in some cases cause a denial of service due to disk exhaustion.