`CVE-2021-21345` XStream

Affected software	XStream
Severity	9.9 Critical CVSS 3.1 3 scores
Fixed in	`1.4.16`
Weakness	Code injection (CWE-94)
Published	23 Mar 2021
Updated	7 Oct 2026

Description

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability which may allow a remote attacker who 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. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.

CWE-502 · Deserialization of untrusted dataCWE-78 · OS command injection

Exploitation status

Working exploit published

A reviewed exploit catalogue lists ready-to-run exploit code for this CVE.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: none
Indexed PoC 1 indexed Published artifacts you can open, in Nuclei.
EPSS 72% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99% of all scored CVEs.

Index	Artifact	Stars	First seen
Nuclei	XStream < 1.4.16 - Remote Code Execution

Index

Artifact

Stars

First seen

Nuclei

XStream < 1.4.16 - Remote Code Execution

Waratek protection

Protected by Waratek

Waratek has a rule that blocks attacks on this vulnerability.

Protection full
Action available security rule
Review human Researcher
Record active

Decided by	Manual classification of this CVE in the legacy dataset
Finding	A manual classification set this CVE's status to Protected by Waratek.

Decided by

Manual classification of this CVE in the legacy dataset

Finding

A manual classification set this CVE's status to Protected by Waratek.

How to mitigate CVE-2021-21345

Upgrade XStream to 1.4.16 or later. Until you can, Waratek RASP blocks exploitation with a security rule that blocks this kind of attack. It runs inside the Java application, with no code changes.

Waratek RASP Runtime protection for Java applications

CVSS

9.9 CRITICAL v3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H 3 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 9.9 CRITICAL CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H NVD Primary published

CVSS 3.1 5.8 MEDIUM CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N security-advisories@github.com Secondary

CVSS 2.0 6.5 none AV:N/AC:L/Au:S/C:P/I:P/A:P NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	9.9	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`	NVD	Primary	published
CVSS 3.1	5.8	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N`	security-advisories@github.com	Secondary
CVSS 2.0	6.5	none	`AV:N/AC:L/Au:S/C:P/I:P/A:P`	NVD	Primary

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update October 2021 ↗	CPU	2021-Q4	Oracle Communications / Policy (XStream) (12.5.0) Oracle Financial Services Applications / Common Core (XStream) (14.2, 14.3, 14.5)
Oracle Critical Patch Update July 2021 ↗	CPU	2021-Q3	Oracle Communications Applications / CN ECE (XStream) (12.0.0.3.0) Oracle Communications Applications / Drools Ruleset (XStream) (7.3.2, 7.3.4, 7.3.5, 7.4.0, 7.4.1) Oracle Financial Services Applications / Collections (XStream) (2.10.0, 2.12.0) Oracle Financial Services Applications / Collections (XStream) (2.4.0, 2.7.1, 2.9.0, 2.12.0) Oracle Fusion Middleware / General (XStream) (11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0) Oracle Fusion Middleware / Security Framework (XStream) (11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0) Oracle Retail Applications / Xenvironment (XStream) (16.0.6, 17.0.4, 18.0.3, 19.0.2)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update October 2021 ↗

CPU

2021-Q4

Oracle Communications / Policy (XStream) (12.5.0)
Oracle Financial Services Applications / Common Core (XStream) (14.2, 14.3, 14.5)

Oracle Critical Patch Update July 2021 ↗

CPU

2021-Q3

Oracle Communications Applications / CN ECE (XStream) (12.0.0.3.0)
Oracle Communications Applications / Drools Ruleset (XStream) (7.3.2, 7.3.4, 7.3.5, 7.4.0, 7.4.1)
Oracle Financial Services Applications / Collections (XStream) (2.10.0, 2.12.0)
Oracle Financial Services Applications / Collections (XStream) (2.4.0, 2.7.1, 2.9.0, 2.12.0)
Oracle Fusion Middleware / General (XStream) (11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0)
Oracle Fusion Middleware / Security Framework (XStream) (11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0)
Oracle Retail Applications / Xenvironment (XStream) (16.0.6, 17.0.4, 18.0.3, 19.0.2)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Communications	Policy (XStream)	12.5.0	12.5.0
Oracle Communications Applications	CN ECE (XStream)	12.0.0.3.0	12.0.0.3.0
Oracle Communications Applications	Drools Ruleset (XStream)	7.3.2, 7.3.4, 7.3.5, 7.4.0, 7.4.1	7.3.2 · 7.3.4 · 7.3.5 · 7.4.0 · 7.4.1
Oracle Financial Services Applications	Collections (XStream)	2.4.0, 2.7.1, 2.9.0, 2.12.0	2.4.0 · 2.7.1 · 2.9.0 · 2.10.0 · 2.12.0
Oracle Financial Services Applications	Common Core (XStream)	14.2, 14.3, 14.5	14.2 · 14.3 · 14.5
Oracle Fusion Middleware	General (XStream)	11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0	11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0
Oracle Fusion Middleware	Security Framework (XStream)	11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0	11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0
Oracle Retail Applications	Xenvironment (XStream)	16.0.6, 17.0.4, 18.0.3, 19.0.2	16.0.6 · 17.0.4 · 18.0.3 · 19.0.2

Family

Component

Versions, as Oracle lists them

Read as

Oracle Communications

Policy (XStream)

12.5.0

Oracle Communications Applications

CN ECE (XStream)

12.0.0.3.0

Oracle Communications Applications

Drools Ruleset (XStream)

7.3.2, 7.3.4, 7.3.5, 7.4.0, 7.4.1

7.3.2 · 7.3.4 · 7.3.5 · 7.4.0 · 7.4.1

Oracle Financial Services Applications

Collections (XStream)

2.4.0, 2.7.1, 2.9.0, 2.12.0

2.4.0 · 2.7.1 · 2.9.0 · 2.10.0 · 2.12.0

Oracle Financial Services Applications

Common Core (XStream)

14.2, 14.3, 14.5

14.2 · 14.3 · 14.5

Oracle Fusion Middleware

General (XStream)

11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0

11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0

Oracle Fusion Middleware

Security Framework (XStream)

11.1.1.9.0, 12.2.1.3.0, 12.2.1.4.0

11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0

Oracle Retail Applications

Xenvironment (XStream)

16.0.6, 17.0.4, 18.0.3, 19.0.2

16.0.6 · 17.0.4 · 18.0.3 · 19.0.2

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

com.thoughtworks.xstream:xstream 0 1.4.16 unbounded

Package	Introduced	Fixed	Last affected
`com.thoughtworks.xstream:xstream`	0	`1.4.16`	unbounded

Products and versions

17 products, 41 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apache	activemq	generic	＜ 5.15.14 · 5.16.0 · 5.16.1
nvd	apache	jmeter	generic	＜ 5.5
osv	com.thoughtworks.xstream	xstream	generic	＜ 1.4.16
nvd	debian	debian linux	generic	9.0 · 10.0 · 11.0
nvd	fedoraproject	fedora	generic	33 · 34 · 35
nvd	netapp	oncommand insight	generic	any version
nvd	oracle	banking enterprise default management	generic	2.10.0 · 2.12.0
nvd	oracle	banking platform	generic	2.4.0 · 2.7.1 · 2.9.0 · 2.12.0
nvd	oracle	banking virtual account management	generic	14.2.0 · 14.3.0 · 14.5.0
nvd	oracle	business activity monitoring	generic	11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0
nvd	oracle	communications billing and revenue management elastic charging engine	generic	12.0.0.3.0
nvd	oracle	communications policy management	generic	12.5.0
nvd	oracle	communications unified inventory management	generic	7.3.2 · 7.3.4 · 7.3.5 · 7.4.0 · 7.4.1
nvd	oracle	peoplesoft enterprise peopletools	generic	8.58 · 8.59
nvd	oracle	retail xstore point of service	generic	16.0.6 · 17.0.4 · 18.0.3 · 19.0.2
nvd	oracle	webcenter portal	generic	11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0
nvd	xstream	xstream	generic	＜ 1.4.16

Source

Vendor

Product

Scheme

Affected versions

nvd

apache

activemq

generic

＜ 5.15.14 · 5.16.0 · 5.16.1

nvd

apache

jmeter

generic

＜ 5.5

osv

com.thoughtworks.xstream

xstream

generic

＜ 1.4.16

nvd

debian

debian linux

generic

9.0 · 10.0 · 11.0

nvd

fedoraproject

fedora

generic

33 · 34 · 35

nvd

netapp

oncommand insight

generic

any version

nvd

oracle

banking enterprise default management

generic

2.10.0 · 2.12.0

nvd

oracle

banking platform

generic

2.4.0 · 2.7.1 · 2.9.0 · 2.12.0

nvd

oracle

banking virtual account management

generic

14.2.0 · 14.3.0 · 14.5.0

nvd

oracle

business activity monitoring

generic

11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0

nvd

oracle

communications billing and revenue management elastic charging engine

generic

12.0.0.3.0

nvd

oracle

communications policy management

generic

12.5.0

nvd

oracle

communications unified inventory management

generic

7.3.2 · 7.3.4 · 7.3.5 · 7.4.0 · 7.4.1

nvd

oracle

peoplesoft enterprise peopletools

generic

8.58 · 8.59

nvd

oracle

retail xstore point of service

generic

16.0.6 · 17.0.4 · 18.0.3 · 19.0.2

nvd

oracle

webcenter portal

generic

11.1.1.9.0 · 12.2.1.3.0 · 12.2.1.4.0

nvd

xstream

generic

＜ 1.4.16

Earlier manual review

A reviewer classified this CVE in an older dataset. We kept the labels and products below, but not the reviewer's reasoning.

## Manual Classification Context **Labels:** DROOLS RULESET (XSTREAM), HTTP, SECURITY FRAMEWORK (XSTREAM), COLLECTIONS (XSTREAM), XENVIRONMENT (XSTREAM), GENERAL (XSTREAM), POLICY (XSTREAM), COMMON CORE (XSTREAM), CN ECE (XSTREAM) **Products:** ORACLE BANKING VIRTUAL ACCOUNT MANAGEMENT, ORACLE BANKING PLATFORM, ORACLE COMMUNICATIONS BRM - ELASTIC CHARGING ENGINE, ORACLE FUSION MIDDLEWARE, ORACLE WEBCENTER PORTAL, ORACLE FINANCIAL SERVICES APPLICATIONS, ORACLE RETAIL XSTORE POINT OF SERVICE, ORACLE COMMUNICATIONS, ORACLE BAM (BUSINESS ACTIVITY MONITORING), ORACLE RETAIL APPLICATIONS, ORACLE COMMUNICATIONS UNIFIED INVENTORY MANAGEMENT, ORACLE BANKING ENTERPRISE DEFAULT MANAGEMENT, ORACLE COMMUNICATIONS APPLICATIONS, ORACLE COMMUNICATIONS POLICY MANAGEMENT

References

URL	Tags
https://github.com/x-stream/xstream/security/advisories/GHSA-hwpc-8xqv-jvj4	WEB
https://x-stream.github.io/security.html#workaround	WEB
https://x-stream.github.io/CVE-2021-21345.html	WEB
https://www.oracle.com/security-alerts/cpuoct2021.html	WEB
https://www.oracle.com/security-alerts/cpujan2022.html	WEB
https://www.oracle.com/security-alerts/cpuApr2021.html	WEB
https://www.oracle.com//security-alerts/cpujul2021.html	WEB
https://www.debian.org/security/2021/dsa-5004	WEB
https://security.netapp.com/advisory/ntap-20210430-0002	WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB	WEB

URL

Timeline

Published	2021-03-23	By the CVE Program.
NVD record modified	2026-10-07	NVD's own last-modified date for this record.

Published

2021-03-23

By the CVE Program.

NVD record modified

2026-10-07

NVD's own last-modified date for this record.

How VRT decided (5 of 24 rules ran)

5 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification decided it matched Protected by Waratek Found in legacy manual classifications

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

NVD ↗ · CVE.org ↗