Grazie, non è problema di "Java Security Manager".
Il mio Tomcat funziona bene con altri WAR.
Scusate che non ho visto prima ma invece vedo errori in catalina.out:
13 Dec 14:02:40 ERROR [context.ContextLoader] - Context initialization failed
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 10 in XML document from URL [jar:file:/var/lib/tomcat7/webapps/geoserver/WEB-INF/lib/main-2.4.2.jar!/applicationSecurityContext.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 10; columnNumber: 85; <Line 10, Column 85>: XML-24500: (Error) Can not build schema '
http://www.springframework.org/schema/security' located at '
http://www.springframework.org/schema/security/spring-security-3.0.4.xsd'
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:396)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:174)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:209)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:131)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:530)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:444)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:388)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:293)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
at org.geoserver.platform.GeoServerContextLoaderListener.contextInitialized(GeoServerContextLoaderListener.java:22)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.manager.ManagerServlet.start(ManagerServlet.java:1256)
at org.apache.catalina.manager.HTMLManagerServlet.start(HTMLManagerServlet.java:714)
at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:219)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:212)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:611)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.xml.sax.SAXParseException; lineNumber: 10; columnNumber: 85; <Line 10, Column 85>: XML-24500: (Error) Can not build schema '
http://www.springframework.org/schema/security' located at '
http://www.springframework.org/schema/security/spring-security-3.0.4.xsd'
at oracle.xml.parser.v2.XMLError.flushErrorHandler(XMLError.java:425)
at oracle.xml.parser.v2.XMLError.flushErrors1(XMLError.java:287)
at oracle.xml.parser.v2.NonValidatingParser.parseDocument(NonValidatingParser.java:343)
at oracle.xml.parser.v2.XMLParser.parse(XMLParser.java:226)
at oracle.xml.jaxp.JXDocumentBuilder.parse(JXDocumentBuilder.java:155)
at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:75)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:388)
... 44 more
Caused by: oracle.xml.parser.schema.XSDException:
www.springframework.org at oracle.xml.parser.schema.XSDBuilder.build(XSDBuilder.java:652)
at oracle.xml.parser.schema.XSDValidator.processSchemaLocation(XSDValidator.java:1003)
at oracle.xml.parser.schema.XSDValidator.startElement(XSDValidator.java:604)
at oracle.xml.parser.v2.NonValidatingParser.parseElement(NonValidatingParser.java:1329)
at oracle.xml.parser.v2.NonValidatingParser.parseRootElement(NonValidatingParser.java:376)
at oracle.xml.parser.v2.NonValidatingParser.parseDocument(NonValidatingParser.java:322)
... 48 more
Dec 13, 2013 2:02:40 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Dec 13, 2013 2:02:40 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/geoserver] startup failed due to previous errors