Vulnerability Report

CVE-2021-43859

Title: Xstream Denial of Service (DoS)

Denial of Service (DoS)

Proof Of Concept

PoC Available for CVE-2021-43859

CWE Category CWE-400
Published Date Feb 01, 2022
Modified Date Nov 03, 2025
Exploit Status Available
Score 7.5 CVSS v3.1
Exploit Probability (EPSS)
7.66%

Vulnerability Summary

CVE-2021-43859: 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.

Impacted Vendors

J
jenkins 1
C
cloudbees 1
O
oracle 7
X
xstream 1

Reference Links

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 https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html https://lists.debian.org/debian-lts-announce/2024/12/msg00023.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
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
5.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:N/C:N/I:N/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-43859 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/andikahilmy/CVE-2021-43859-xstream-vulnerable
View Code
MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Stack

No specific products linked.