CVEs-PoC/2021/CVE-2021-43859.md

### [CVE-2021-43859](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43859)
![](https://img.shields.io/static/v1?label=Product&message=xstream&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3C%201.4.19%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-400%3A%20Uncontrolled%20Resource%20Consumption&color=brightgreen)

### Description

XStream is an open source java library to serialize objects to XML and back again. Versions prior to 1.4.19 may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. XStream 1.4.19 monitors and accumulates the time it takes to add elements to collections and throws an exception if a set threshold is exceeded. Users are advised to upgrade as soon as possible. Users unable to upgrade may set the NO_REFERENCE mode to prevent recursion. See GHSA-rmr5-cpv2-vgjf for further details on a workaround if an upgrade is not possible.

### POC

#### Reference
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html

#### Github
- https://github.com/20142995/nuclei-templates
- https://github.com/ARPSyndicate/cvemon
- https://github.com/cyb3r-w0lf/nuclei-template-collection
- https://github.com/muneebaashiq/MBProjects
- https://github.com/r00t4dm/r00t4dm
- https://github.com/rootameen/vulpine