Bingo. Reconfigurei o usuário de acesso ao banco para a aplicação e resolvi esse problema, mas como nem tudo são flores, agora me deparo com esse erro:
09-Nov-2017 09:29:36.109 ADVERTÊNCIA [http-nio-8080-exec-6] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [catracas] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister ister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
09-Nov-2017 09:29:36.110 ADVERTÊNCIA [http-nio-8080-exec-6] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [catracas] appears to have started a thread named [Abandoned connection cleanup threp thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:64)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)