CVE-2021-21348 XStream is vulnerable to an attack using Regular Expression for a Denial of Service (ReDos)
Remote attackers can cause denial of service by triggering excessive CPU consumption via regular expressions in XStream.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-21348?
CVE-2021-21348 is a medium-severity denial of service 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 which may allow a remote attacker to occupy a thread that consumes maximum CPU time and will never return. 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.
Which versions are affected by CVE-2021-21348?
3 open source packages ship an affected version, including activemq and com.thoughtworks.xstream:xstream. It affects 16 products.
| Package | Affected | Fixed in |
|---|---|---|
activemq Bitnami | All versions to 5.16.0 | 5.15.14 |
com.thoughtworks.xstream:xstream Maven | All versions | 1.4.16 |
com.thoughtworks.xstream:xstream Maven | All versions | 1.4.16 |
Products include Apache Activemq, Apache Jmeter, Debian Debian Linux, Fedoraproject Fedora, Netapp Oncommand Insight, Oracle Banking Enterprise Default Management and 10 more.
How do I fix CVE-2021-21348?
Upgrade activemq to 5.15.14 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-21348 being exploited?
There is no known exploitation of CVE-2021-21348 in the wild and no public exploit code.
Other vulnerabilities in Apache Activemq
Sources
Also known as BIT-activemq-2021-21348, DEBIAN-CVE-2021-21348, GHSA-56p8-3fh9-4cvq, UBUNTU-CVE-2021-21348.