The request was rejected because the URL contained a potentially malicious String

[a-camacho]

Describe the bug
We see some errors in SEB Server logs regarding potentially malicious strings.
We don't really know if they come from bots or if they are malformed requests in SEB Client / SEB Server.

To Reproduce
Steps to reproduce the behavior:

1. Use Moodle and SEB Server and do an exam
2. See logs of sebserver container

Expected behavior
No error logs.

Logs

12:11:59.831 ERROR [http-nio-0.0.0.0-8080-exec-8]:[org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet]] Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception
org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String ";"
	at org.springframework.security.web.firewall.StrictHttpFirewall.rejectedBlocklistedUrls(StrictHttpFirewall.java:535)
	at org.springframework.security.web.firewall.StrictHttpFirewall.getFirewalledRequest(StrictHttpFirewall.java:505)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:206)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:186)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153)
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153)
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:96)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	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:390)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:926)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1791)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.base/java.lang.Thread.run(Unknown Source)

Setup (please complete the following information):

• Moodle 4.4.3
• SEB Server integration 2024091300
• SEB Server Version 2.0.2
• OS : MacOS and Windows (?)

[nexterday]

Cross-reference

[anhefti]

Hi

I hardly can think of that this come from the referenced Issue but also cannot completely rule it out. But for the functionality, there is no need from a SEB client to call SEB Server API with URL that contains a semicolon ";". If SEB client sends this to SEB Server it might be by accident.

Question; does it only happen when SEB clients are connected, or does it also happen on other random events?

I can make the internal Spring based firewall configurable for the next SEB Server version that comes end of August. So that you can configure SEB Server to ignore ";" in URL and let the call thought the firewall.