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OpenAdvisories
Medium · 6.1 Public exploit CVE-2021-21349 BIT-activemq-2021-21349EUVD-2021-0651GHSA-f6hm-88x3-mfjv

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

Published Mar 22, 2021 · Updated Oct 7, 2026 · Assigned by GitHub_M

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 request data from internal resources that are not publicly available only by manipulating the processed input stream. 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.

Affected products

VendorProductAffectedFixed
x-stream xstream < 1.4.16 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 libxstream-java 1.4.15-2 —
Debian 13 libxstream-java 1.4.15-2 —
Debian 12 libxstream-java 1.4.15-2 —
Debian 9 libxstream-java 1.4.11.1-1+deb9u2 DLA-2616-1
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS libxstream-java 1.4.11.1-1ubuntu0.2 USN-4943-1
Ubuntu 18.04 LTS libxstream-java 1.4.11.1-1~18.04.2 USN-4943-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 16.04 LTS libxstream-java 1.4.8-1ubuntu0.1+esm3 USN-6978-1
Ubuntu Pro 14.04 LTS libxstream-java 1.4.7-1ubuntu0.1+esm2 USN-6978-1
ReleasePackageFixed inAdvisory
SLES 15 SP3 xstream 1.4.16-3.8.1 SUSE-SU-2021:1840-1
SLES 15 SP2 xstream 1.4.16-3.8.1 SUSE-SU-2021:1840-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SUSE Manager Server Module 4.2 xstream 1.4.16-3.8.1 SUSE-SU-2021:1840-2
SUSE Manager Server Module 4.1 xstream 1.4.16-3.8.1 SUSE-SU-2021:1840-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed xstream 1.4.18-1.1 openSUSE-SU-2024:10592-1
openSUSE Leap 15.3 xstream 1.4.16-3.8.1 openSUSE-SU-2021:1840-1
openSUSE Leap 15.2 xstream 1.4.16-lp152.2.6.1 openSUSE-SU-2021:0832-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2 xstream +1 1.3.1-13.amzn2 ALAS2-2021-1645

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Affected packages

EcosystemPackageAffectedFixedRecord
Maven com.thoughtworks.xstream:xstream < 1.4.16 1.4.16 GHSA-f6hm-88x3-mfjv

Advisories 10

References