s-index/cve-2021-21341XStream DoS CVE-2021-21341
Vulnerability
CVE-2021-21341: XStream can cause a Denial of Service.
Affected Versions
All versions until and including version 1.4.15 are affected, if using the version out of the box. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types.
Description
The processed stream at unmarshalling time contains type information to recreate the formerly written objects. XStream creates therefore new instances based on these type information. An attacker can manipulate the processed input stream and replace or inject a manipulated ByteArrayInputStream (or derived class), that can cause an endless loop resulting in a denial of service.
$ docker build -t cve-2021-21341 .
$ docker run -it --rm cve-2021-21341
Security framework of XStream not explicitly initialized, using predefined black list on your own risk.
(never end)
Change pom.xml to bellow
<dependency>
<groupId>com.thoughtworks.xstream</groupId>
<artifactId>xstream</artifactId>
<version>1.4.16</version>
</dependency>
Add NoTypePermission.NONE
import com.thoughtworks.xstream.security.NoTypePermission; // Add
XStream xstream = new XStream();
xstream.addPermission(NoTypePermission.NONE); // Add
xstream.fromXML(xml);