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Fencer Intel
medium 5.3

CVE-2021-21342 json

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 5y ago modified last mo. also BIT-activemq-2021-21342 , EUVD-2021-0673 , GHSA-hvv8-336g-rx3m

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
50.0%
EPSS 50.0% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven com.thoughtworks.xstream:xstream 1.4.16
  • bitnami activemq 5.15.14
  • apache activemq 5.15.14
  • apache jmeter 5.5
  • xstream xstream 1.4.16
  • libxstream-java Debian 14, Debian 13, Debian 12 1.4.15-2

debian advisories DEBIAN-CVE-2021-21342

  • libxstream-java Ubuntu 18.04 LTS 1.4.11.1-1~18.04.2
  • libxstream-java Ubuntu 20.04 LTS 1.4.11.1-1ubuntu0.2
  • libxstream-java Ubuntu Pro 14.04 LTS 1.4.7-1ubuntu0.1+esm2
  • libxstream-java Ubuntu Pro 16.04 LTS 1.4.8-1ubuntu0.1+esm3

ubuntu advisories UBUNTU-CVE-2021-21342

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xstream SLE Module for Development Tools 15 SP3, SLE Module for Development Tools 15 SP2, Manager Server Module 4.2 +1 more 1.4.16-3.8.1

suse advisories SUSE-SU-2021:1840-2SUSE-SU-2021:1840-1

  • xstream openSUSE Tumbleweed 1.4.18-1.1
  • xstream openSUSE Leap 15.3 1.4.16-3.8.1
  • xstream openSUSE Leap 15.2 1.4.16-lp152.2.6.1

opensuse advisories openSUSE-SU-2024:10592-1openSUSE-SU-2021:1840-1openSUSE-SU-2021:0832-1

Is CVE-2021-21342 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-21342 updated cvss 7.4

XStream: SSRF via crafted input stream

  • Red Hat BPM Suite 6 xstream Red Hat Enterprise Linux 7 xstream, xstream-javadoc
    affected: no fix planned “Out of support scope”
  • Red Hat Integration Camel K 1 xstream Red Hat Integration Camel Quarkus 1 xstream
    affected: no fix available
  • Red Hat JBoss A-MQ 6 xstream Red Hat JBoss BRMS 5 xstream Red Hat JBoss BRMS 6 xstream Red Hat JBoss Data Grid 7 xstream Red Hat JBoss Data Virtualization 6 xstream Red Hat JBoss Fuse 6 xstream
    +2 more products
    Red Hat JBoss Fuse Service Works 6 xstream Red Hat JBoss SOA Platform 5 xstream
    affected: no fix planned “Out of support scope”
  • Red Hat Data Grid 8.2.0
    fixed: vendor fix RHSA-2021:2139
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
  • Red Hat Integration
    fixed: vendor fix RHSA-2021:4918
  • Red Hat Integration Camel Quarkus 2
    fixed: vendor fix RHSA-2021:4767
  • Red Hat RHDM 7.11.0
    fixed: vendor fix RHSA-2021:2476
show 2 more
  • Red Hat RHPAM 7.11.0
    fixed: vendor fix RHSA-2021:2475
  • Red Hat OpenShift Container Platform 3.11 jenkins Red Hat OpenShift Container Platform 4 jenkins
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last mo.

Exploit prediction

49.99% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • x-stream.github.io https://x-stream.github.io/CVE-2021-21342.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N
OSV 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven com.thoughtworks.xstream:xstream
<1.4.16
1.4.16
bitnami activemq
<5.15.14
>=5.16.0, <=5.16.0
>=5.16.1, <=5.16.1
5.15.14

Affected products

  • x-stream xstream

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
  • CWE-918 Server-Side Request Forgery

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.