Subject: bug#437: tomcat8: Tomcat8 fix for CVE-2020-1938 breaks compatibility with Apache2 mod_proxy_ajp

From: Gianluca Bonetti <[email-masked]>
Date: Mon, 04 May 2020 21:54:35 +0200

Package: tomcat8
Version: 8.5.54-0+deb9u1
Severity: grave

Dear Maintainer,

Last tomcat8 upgrade, fixing CVE-2020-1938, is breaking the functionalities of Tomcat AJP connector
in standard setup.
The updated tomcat8 version implements 'secretRequired' parameter in <Connector> tag for config file
/etc/tomcat8/server.xml (attached by reportbut) and the implicit default for 'secretRequired' is true.
The default value is not explicitly marked in the standard server.xml, nor documented there.

However, current apache2 package version 2.4.25-3+deb9u9 does not support secret in mod_proxy_ajp.
Hence, to get a working system using AJP, secretRequired has to be set to false in server.xml

Apache2 mod_proxy_ajp supports secret since version 2.5, backported to 2.4.42.
https://httpd.apache.org/docs/trunk/mod/mod_proxy_ajp.html
https://httpd.apache.org/docs/2.4/mod/mod_proxy_ajp.html

The solution is either to upgrade the apache2 package, or to have the default for 'secretRequired' set
to 'false', with some comments in the server.xml itself.
The standard configuration accepts AJP connections from localhost only, and/or iptables rules can
applied as well.

Adding relevant part of catalina.out to this bug report.

Thank you
Cheers
Gianluca Bonetti

-- System Information:
Debian Release: 9
Architecture: amd64
 (x86_64)

Kernel: Linux 4.9.0-12-amd64 (SMP w/8 CPU cores)
Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages tomcat8 depends on:
ii  adduser                3.115
ii  debconf [debconf-2.0]  1.5.61
ii  lsb-base               4.1+devuan2
ii  tomcat8-common         8.5.54-0+deb9u1
ii  ucf                    3.0036

Versions of packages tomcat8 recommends:
ii  authbind       2.1.2
ii  libtcnative-1  1.2.21-1~deb9u1

Versions of packages tomcat8 suggests:
pn  tomcat8-admin     <none>
pn  tomcat8-docs      <none>
pn  tomcat8-examples  <none>
pn  tomcat8-user      <none>

-- Configuration Files:
/etc/tomcat8/server.xml changed:
<?xml version="1.0" encoding="UTF-8"?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at
      http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<!-- Note:  A "Server" is not itself a "Container", so you may not
     define subcomponents such as "Valves" at this level.
     Documentation at /docs/config/server.html
 -->
<Server port="8005" shutdown="SHUTDOWN">
  <Listener className="org.apache.catalina.startup.VersionLoggerListener" />
  <!-- Security listener. Documentation at /docs/config/listeners.html
  <Listener className="org.apache.catalina.security.SecurityListener" />
  -->
  <!--APR library loader. Documentation at /docs/apr.html -->
  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
  <!-- Prevent memory leaks due to use of particular java/javax APIs-->
  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
  <Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
  <!-- Global JNDI resources
       Documentation at /docs/jndi-resources-howto.html
  -->
  <GlobalNamingResources>
    <!-- Editable user database that can also be used by
         UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase" auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
  </GlobalNamingResources>
  <!-- A "Service" is a collection of one or more "Connectors" that share
       a single "Container" Note:  A "Service" is not itself a "Container",
       so you may not define subcomponents such as "Valves" at this level.
       Documentation at /docs/config/service.html
   -->
  <Service name="Catalina">
    <!--The connectors can use a shared executor, you can define one or more named thread pools-->
    <!--
    <Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
        maxThreads="150" minSpareThreads="4"/>
    -->
    <!-- A "Connector" represents an endpoint by which requests are received
         and responses are returned. Documentation at :
         Java HTTP Connector: /docs/config/http.html
         Java AJP  Connector: /docs/config/ajp.html
         APR (HTTP/AJP) Connector: /docs/apr.html
         Define a non-SSL/TLS HTTP/1.1 Connector on port 8080
    -->
    <!--
    <Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    -->
    <!-- A "Connector" using the shared thread pool-->
    <!--
    <Connector executor="tomcatThreadPool"
               port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    -->
    <!-- Define an SSL/TLS HTTP/1.1 Connector on port 8443
         This connector uses the NIO implementation. The default
         SSLImplementation will depend on the presence of the APR/native
         library and the useOpenSSL attribute of the
         AprLifecycleListener.
         Either JSSE or OpenSSL style configuration may be used regardless of
         the SSLImplementation selected. JSSE style configuration is used below.
    -->
    <!--
    <Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
               maxThreads="150" SSLEnabled="true">
        <SSLHostConfig>
            <Certificate certificateKeystoreFile="conf/localhost-rsa.jks"
                         type="RSA" />
        </SSLHostConfig>
    </Connector>
    -->
    <!-- Define an SSL/TLS HTTP/1.1 Connector on port 8443 with HTTP/2
         This connector uses the APR/native implementation which always uses
         OpenSSL for TLS.
         Either JSSE or OpenSSL style configuration may be used. OpenSSL style
         configuration is used below.
    -->
    <!--
    <Connector port="8443" protocol="org.apache.coyote.http11.Http11AprProtocol"
               maxThreads="150" SSLEnabled="true" >
        <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />
        <SSLHostConfig>
            <Certificate certificateKeyFile="conf/localhost-rsa-key.pem"
                         certificateFile="conf/localhost-rsa-cert.pem"
                         certificateChainFile="conf/localhost-rsa-chain.pem"
                         type="RSA" />
        </SSLHostConfig>
    </Connector>
    -->
    <!-- Define an AJP 1.3 Connector on port 8009 -->
    <Connector protocol="AJP/1.3"
               secretRequired="false"
               address="127.0.0.1"
               port="8009"
               redirectPort="8443" />
    <!-- An Engine represents the entry point (within Catalina) that processes
         every request.  The Engine implementation for Tomcat stand alone
         analyzes the HTTP headers included with the request, and passes them
         on to the appropriate Host (virtual host).
         Documentation at /docs/config/engine.html -->
    <!-- You should set jvmRoute to support load-balancing via AJP ie :
    <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
    -->
    <Engine name="Catalina" defaultHost="localhost">
      <!--For clustering, please take a look at documentation at:
          /docs/cluster-howto.html  (simple how to)
          /docs/config/cluster.html (reference documentation) -->
      <!--
      <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
      -->
      <!-- Use the LockOutRealm to prevent attempts to guess user passwords
           via a brute-force attack -->
      <Realm className="org.apache.catalina.realm.LockOutRealm">
        <!-- This Realm uses the UserDatabase configured in the global JNDI
             resources under the key "UserDatabase".  Any edits
             that are performed against this UserDatabase are immediately
             available for use by the Realm.  -->
        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
               resourceName="UserDatabase"/>
      </Realm>
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
        <!-- SingleSignOn valve, share authentication between web applications
             Documentation at: /docs/config/valve.html -->
        <!--
        <Valve className="org.apache.catalina.authenticator.SingleSignOn" />
        -->
        <!-- Access log processes all example.
             Documentation at: /docs/config/valve.html
             Note: The pattern used is equivalent to using pattern="common" -->
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log" suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
    </Engine>
  </Service>
</Server>

-- debconf information:
  tomcat8/username: tomcat8
  tomcat8/javaopts: -Djava.awt.headless=true -Xms8g -Xmx8g -XX:+UseG1GC -Dserver=1 -Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n
  tomcat8/groupname: tomcat8

-- catalina.out:
04-May-2020 19:49:31.629 GRAVE [main] org.apache.catalina.core.StandardService.startInternal Failed to start connector [Connector[AJP/1.3-8009]]
        org.apache.catalina.LifecycleException: Protocol handler start failed
                at org.apache.catalina.connector.Connector.startInternal(Connector.java:1086)
                at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
                at org.apache.catalina.core.StandardService.startInternal(StandardService.java:440)
                at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
                at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:766)
                at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
                at org.apache.catalina.startup.Catalina.start(Catalina.java:688)
                at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
                at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
                at java.lang.reflect.Method.invoke(Method.java:498)
                at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
                at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)
        Caused by: java.lang.IllegalArgumentException: The AJP Connector is configured with secretRequired="true" but the secret attribute is either null or "". This combination is not valid.
                at org.apache.coyote.ajp.AbstractAjpProtocol.start(AbstractAjpProtocol.java:274)
                at org.apache.catalina.connector.Connector.startInternal(Connector.java:1083)
                ... 12 more
04-May-2020 19:49:31.630 INFORMAZIONI [main] org.apache.catalina.startup.Catalina.start Server startup in 6947 ms

---

From: Mark Hindley <[email-masked]>
Date: Tue, 5 May 2020 09:22:30 +0100

Control: tags -1 debian

> Last tomcat8 upgrade, fixing CVE-2020-1938, is breaking the functionalities of Tomcat AJP connector

Gianluca,

Thanks for this. However neither tomcat8 nor apache2 are forked packages in
Devuan and we use Debian's packages directly.

Please report this issue directly to Debian's BTS.

Thanks

Mark

---

From: Mark Hindley <[email-masked]>
Date: Tue, 5 May 2020 09:27:34 +0100

> Control: tags -1 debian

https://bugs.debian.org/959747

---

From: "Devuan bug Tracking System" <[email-masked]>
Date: Tue, 02 Jul 2024 07:12:02 +0000

This is an automatic notification regarding your bug report
which was filed against the tomcat8 package:

#437: tomcat8: Tomcat8 fix for CVE-2020-1938 breaks compatibility with Apache2 mod_proxy_ajp

It has been closed by Mark Hindley <[email-masked]>.

Their explanation is attached below along with your original report.
If this explanation is unsatisfactory and you have not received a
better one in a separate message then please contact Mark Hindley <[email-masked]> by
replying to this email.

-- 
437: https://bugs.devuan.org/cgi/bugreport.cgi?bug=437
Devuan Bug Tracking System
Contact [email-masked] with problems

Subject: Closed in in Debian #959747
From: Mark Hindley <[email-masked]>
To: [email-masked]
Date: Tue, 2 Jul 2024 08:09:35 +0100

Tomcat8 removed in Debian. Closing related bugs.

Mark

Subject: tomcat8: Tomcat8 fix for CVE-2020-1938 breaks compatibility with Apache2 mod_proxy_ajp
From: Gianluca Bonetti <[email-masked]>
To: Devuan Bug Tracking System <[email-masked]>
Date: Mon, 04 May 2020 21:54:35 +0200

Package: tomcat8
Version: 8.5.54-0+deb9u1
Severity: grave

Dear Maintainer,

Thank you
Cheers
Gianluca Bonetti

-- System Information:
Debian Release: 9
Architecture: amd64
 (x86_64)

-- Configuration Files:

-- debconf information:

-- catalina.out: