CVE-2021-21342 A Server-Side Forgery Request can be activated unmarshalling with XStream to access data streams from an arbitrary URL referencing a resource in an intranet or the local host

What is CVE-2021-21342?

CVE-2021-21342 is a medium-severity server-side request forgery vulnerability in Apache Activemq, published on 22 Mar 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability where 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 objects, that result in a server-side forgery request. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.

Weakness: CWE-918, CWE-502

Which versions are affected by CVE-2021-21342?

3 open source packages ship an affected version, including activemq and com.thoughtworks.xstream:xstream. It affects 15 products.

Products include Apache Activemq, Apache Jmeter, Debian Debian Linux, Fedoraproject Fedora, Netapp Oncommand Insight, Oracle Banking Enterprise Default Management and 9 more.

How do I fix CVE-2021-21342?

Upgrade activemq to 5.15.14 or later.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2021-21342 being exploited?

There is no known exploitation of CVE-2021-21342 in the wild and no public exploit code.

Other vulnerabilities in Apache Activemq

• CVE-2023-46604 Apache ActiveMQ Deserialization of Untrusted Data Exploited Critical 10.0
• CVE-2016-3088 Apache ActiveMQ Improper Input Validation Exploited Critical 9.8
• CVE-2026-34197 Apache ActiveMQ Improper Input Validation Exploited High 8.8
• CVE-2020-11998 Remote code execution in Apache ActiveMQ Critical 9.8
• CVE-2013-7285 Command Injection in Xstream Critical 9.8

All Apache Activemq vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-activemq-2021-21342, DEBIAN-CVE-2021-21342, GHSA-hvv8-336g-rx3m, UBUNTU-CVE-2021-21342.