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
Impact
The vulnerability 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.
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-2021-21349.
Credits
The vulnerability was discovered and reported by threedr3am.
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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | com.thoughtworks.xstream:xstream | < 1.4.16 | 1.4.16 |
References
- https://github.com/x-stream/xstream/security/advisories/GHSA-f6hm-88x3-mfjv
- https://nvd.nist.gov/vuln/detail/CVE-2021-21349
- https://github.com/x-stream/xstream
- https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd@%3Cusers.activemq.apache.org%3E
- https://lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0@%3Cdev.jmeter.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/04/msg00002.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB
- https://security.netapp.com/advisory/ntap-20210430-0002
- https://www.debian.org/security/2021/dsa-5004
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://x-stream.github.io/CVE-2021-21349.html
- https://x-stream.github.io/security.html#workaround
- http://x-stream.github.io/changes.html#1.4.16
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N- Weakness (CWE)
CWE-502, CWE-918- Platform
- Java / Kotlin (Maven)
- Package
com.thoughtworks.xstream:xstream- Disclosed
- 22.03.2021
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-f6hm-88x3-mfjv - CC BY 4.0
Vulnerability history: com.thoughtworks.xstream:xstream
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 37
- First → latest
- 05.2019 11.2024
- Without a fix
- 0
- Exploited in attacks
- 1
Severity breakdown
- Critical 2
- High 22
- Medium 13
Disclosures per year
- 2019: 2
- 2020: 5
- 2021: 26
- 2022: 3
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 0
-
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 this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.