What’s Vulnerable › Vulnerabilities
CVE-2021-43859: Denial of Service by injecting highly recursive collections or maps in XStream
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 7.9% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2022-02-01 · updated 2026-06-17
- Weakness: CWE-400
Description
XStream is an open source java library to serialize objects to XML and back again. Versions prior to 1.4.19 may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. XStream 1.4.19 monitors and accumulates the time it takes to add elements to collections and throws an exception if a set threshold is exceeded. Users are advised to upgrade as soon as possible. Users unable to upgrade may set the NO_REFERENCE mode to prevent recursion. See GHSA-rmr5-cpv2-vgjf for further details on a workaround if an upgrade is not possible.
Affected products
- Debian Linux: 9.0
- Fedoraproject Fedora: 34, 35
- Jenkins: before 2.319.3; from 2.321 before 2.334 — fixed in 2.319.3, 2.334
- Oracle Corporation Oracle Commerce Guided Search / Oracle Commerce Experience Manager: 11.3.2
- Oracle Corporation Communications BRM - Elastic Charging Engine: before 12.0.0.4.6; 12.0.0.5.0 — fixed in 12.0.0.4.6
- Oracle Communications Cloud Native Core Automated Test Suite: 1.9.0
- Oracle Communications Diameter Intelligence Hub: from 8.0.0 through 8.1.0; from 8.2.0 through 8.2.6
- Oracle Corporation Communications Policy Management: 12.6.0.0.0
- Oracle Corporation FLEXCUBE Private Banking: 12.1.0
- Oracle Corporation Retail Xstore Point of Service: 16.0.6, 17.0.4, 18.0.3, 19.0.2, 20.0.1
- x-stream xstream: before 1.4.19 — fixed in 1.4.19
How to fix
Upgrade to a fixed version: Jenkins 2.319.3, 2.334; Oracle Corporation Communications BRM - Elastic Charging Engine 12.0.0.4.6; x-stream xstream 1.4.19. Check the vendor advisory for mitigations.
References
- http://www.openwall.com/lists/oss-security/2022/02/09/1
- https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846
- https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf
- https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VACQYG356OHUTD5WQGAQ4L2TTFTAV3SJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XODFRE2ZL64FICBJDOPWOLPTSSAI4U7X/
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://x-stream.github.io/CVE-2021-43859.html
- http://www.openwall.com/lists/oss-security/2022/02/09/1
- https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846
- https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf
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