XStream is vulnerable to a Remote Command Execution attackGHSA-hwpc-8xqv-jvj4
MEDIUMGHSA-hwpc-8xqv-jvj4 is a medium-severity (CVSS 5.8) Code Injection vulnerability in com.thoughtworks.xstream:xstream. 1 public exploit reference exists, so weaponization risk is real. A fix is available for com.thoughtworks.xstream:xstream — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hwpc-8xqv-jvj4.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-hwpc-8xqv-jvj4 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
com.thoughtworks.xstream:xstreamReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The vulnerability may allow a remote attacker has sufficient rights to execute commands of the host 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.
Patches
If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.
Workarounds
See workarounds for the different versions covering all CVEs.
References
See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for CVE-2021-21345.
Credits
钟潦贵 (Liaogui Zhong) found and reported the issue to XStream and provided the required information to reproduce it.
For more information
If you have any questions or comments about this advisory:
- Open an issue in XStream
- Contact us at XStream Google Group
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.thoughtworks.xstream:xstream | all versions | 1.4.16com.thoughtworks.xstream:xstream:1.4.16 |
Affected Products
activemqapachejmeterapachedebian linuxdebianfedorafedoraprojectoncommand insightnetappbanking enterprise default managementoracleResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.thoughtworks.xstream:xstream, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.thoughtworks.xstream:xstream to 1.4.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hwpc-8xqv-jvj4 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
How to detect GHSA-hwpc-8xqv-jvj4
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-hwpc-8xqv-jvj4 -u https://target- Template
- XStream < 1.4.16 - Remote Code Execution
- Severity
- critical
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the target system.
- Remediation
- Install at least 1.4.16 if you rely on XStream's default blacklist of the Security Framework.
Template by ProjectDiscovery nuclei-templates (pwnhxl, vicrack), MIT licensed. View the full template. Scan only systems you are authorised to test.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
OpenShift Container Platform (OCP) delivers Jenkins LTS package with bundled XStream library. Due to JEP-200 [1] and JEP-228 [2] Jenkins projects, OCP Jenkins package is not affected by this flaw. [1] https://github.com/jenkinsci/jep/blob/master/jep/200/README.adoc [2]…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Data Grid 8.2.0 | xstream | RHSA-2021:2139 |
| Red Hat Enterprise Linux 7 | xstream-0:1.3.1-13.el7_9 | RHSA-2021:1354 |
| Red Hat Fuse 7.10 | xstream | RHSA-2021:5134 |
| Red Hat Integration | see advisory | RHSA-2021:4918 |
| Red Hat Integration Camel Quarkus 2 | see advisory | RHSA-2021:4767 |
| RHDM 7.11.0 | xstream | RHSA-2021:2476 |
| RHPAM 7.11.0 | xstream | RHSA-2021:2475 |
Frequently Asked Questions
Is GHSA-hwpc-8xqv-jvj4 in your dependencies?
Find it across Maven, including transitive dependencies.