NPE when entering invalid code in SMSOTP in WSO2IS - multi-factor-authentication

Question

I am trying to enable SMSOTP (in 5.10.0) following this guide https://is.docs.wso2.com/en/5.10.0/learn/configuring-sms-otp/#configuring-sms-otp. When I enter a valid code (that I received via sms) I am getting logged-in successfully.
But, when I enter any invalid code, I am getting redirected to a page with the following message (without any option to re-enter the code):
Authentication Error!
Something went wrong during the authentication process. Please try signing in again.
At the same time the following exception gets written in IS's logs:
[2021-01-05 14:13:48,155] [daa6f5a8-720e-4981-9c1a-23014f0eec59] ERROR {org.wso2.carbon.identity.application.authentication.framework.handler.request.impl.DefaultRequestCoordinator} - Exception in Authentication Framework java.lang.NullPointerException
at org.wso2.carbon.identity.application.authentication.framework.AbstractApplicationAuthenticator.publishAuthenticationStepAttempt(AbstractApplicationAuthenticator.java:170)
at org.wso2.carbon.identity.application.authentication.framework.AbstractApplicationAuthenticator.process(AbstractApplicationAuthenticator.java:94)
at org.wso2.carbon.identity.authenticator.smsotp.SMSOTPAuthenticator.process(SMSOTPAuthenticator.java:128)
at org.wso2.carbon.identity.application.authentication.framework.handler.step.impl.DefaultStepHandler.doAuthentication(DefaultStepHandler.java:506)
at org.wso2.carbon.identity.application.authentication.framework.handler.step.impl.DefaultStepHandler.handleResponse(DefaultStepHandler.java:480)
at org.wso2.carbon.identity.application.authentication.framework.handler.step.impl.DefaultStepHandler.handle(DefaultStepHandler.java:179)
at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handleAuthenticationStep(GraphBasedSequenceHandler.java:417)
at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handleNode(GraphBasedSequenceHandler.java:172)
at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handle(GraphBasedSequenceHandler.java:127)
at org.wso2.carbon.identity.application.authentication.framework.handler.request.impl.DefaultAuthenticationRequestHandler.handle(DefaultAuthenticationRequestHandler.java:158)
at org.wso2.carbon.identity.application.authentication.framework.handler.request.impl.DefaultRequestCoordinator.handle(DefaultRequestCoordinator.java:240)
at org.wso2.carbon.identity.application.authentication.framework.servlet.CommonAuthenticationServlet.doPost(CommonAuthenticationServlet.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.eclipse.equinox.http.helper.ContextPathServletAdaptor.service(ContextPathServletAdaptor.java:37)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:60)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.service(DelegationServlet.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.wso2.carbon.identity.captcha.filter.CaptchaFilter.doFilter(CaptchaFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.owasp.csrfguard.CsrfGuardFilter.doFilter(CsrfGuardFilter.java:72)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.wso2.carbon.tomcat.ext.filter.CharacterSetFilter.doFilter(CharacterSetFilter.java:65)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.filters.HttpHeaderSecurityFilter.doFilter(HttpHeaderSecurityFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.wso2.carbon.identity.context.rewrite.valve.TenantContextRewriteValve.invoke(TenantContextRewriteValve.java:86)
at org.wso2.carbon.identity.authz.valve.AuthorizationValve.invoke(AuthorizationValve.java:110)
at org.wso2.carbon.identity.auth.valve.AuthenticationValve.invoke(AuthenticationValve.java:75)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.continueInvocation(CompositeValve.java:99)
at org.wso2.carbon.tomcat.ext.valves.TomcatValveContainer.invokeValves(TomcatValveContainer.java:49)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:62)
at org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:145)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688)
at org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:57)
at org.wso2.carbon.tomcat.ext.valves.RequestEncodingValve.invoke(RequestEncodingValve.java:49)
at org.wso2.carbon.tomcat.ext.valves.RequestCorrelationIdValve.invoke(RequestCorrelationIdValve.java:119)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:834)
I have two questions:
Is it expected to get redirected to that error page without any option to re-enter the code?
Is the exception written in the logs something that's causing the redirection to that error page while the system would have behaved differently (e.g. showing a page where the user would be able to re-enter the code) if there was no NPE?
Thank you

Answer 1

This seems to be a known issue and already fixed in 5.10.0 with WSO2 updates. But, you might need to have a paid subscription to obtain that.
Please refer to the Git issue here
Or else, you can try the 5.11.0 release which includes this fix.