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CVE-2021-21346

74
FAUCET Score

CVE-2021-21346 is a critical vulnerability in XStream, a Java library for XML serialization, affecting versions prior to 1.4.16. This flaw allows a remote attacker to execute arbitrary code by manipulating the input stream, impacting products from vendors like Apache, Debian, Oracle, and NetApp. With a CVSS score of 9.8 (Critical), it presents a severe risk due to its network-based attack vector, low attack complexity, and complete compromise of confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community discussion, indicating awareness and potential for future exploitation.

Impacted Technologies

VendorProductVersion(s)CPE
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
< 5.15.14CPE matchmatch criteria
cpe:2.3:a:apache:activemq:*:*:*:*:*:*:*:*
5.16.0CPE matchmatch criteria
cpe:2.3:a:apache:activemq:5.16.0:*:*:*:*:*:*:*
5.16.1CPE matchmatch criteria
cpe:2.3:a:apache:activemq:5.16.1:*:*:*:*:*:*:*
< 5.5CPE matchmatch criteria
cpe:2.3:a:apache:jmeter:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.1MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
1.6
Impact Score
4.0
CvssVersion
3.1

Exploit Intelligence

EPSS Score
76.37%
Probability of exploitation in next 30 days
EPSS Percentile
99.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.7637 is in the 98th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (11)

mavenpatch availablevia ghsa
Product: com.thoughtworks.xstream:xstreamFixed in: 1.4.16
oraclepatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xstream-0:1.3.1-13.el7_9
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Fuse 7.10Fixed in: xstream
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Integration Camel Quarkus 2
View patch
redhatpatch availablevia redhat_api
Product: RHDM 7.11.0Fixed in: xstream
View patch
redhatpatch availablevia redhat_api
Product: RHPAM 7.11.0Fixed in: xstream
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Integration
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Data Grid 8.2.0Fixed in: xstream
View patch
redhatno patchvia redhat_api
Product: Red Hat Integration Camel K 1Fixed in: xstream
redhatno patchvia redhat_api
Product: Red Hat Integration Camel Quarkus 1Fixed in: xstream

Vendor Advisories (2)

mavenGHSA-4hrm-m67v-5cxrmedium

XStream is vulnerable to an Arbitrary Code Execution attack

Mar 22, 2021
redhatCVE-2021-21346Important

XStream: Unsafe deserizaliation of sun.swing.SwingLazyValue

Mar 12, 2021

References

github.com / x-stream/xstream/security/advisories/GHSA-4hrm-m67v-5cxr
Third Party Advisory
lists.apache.org / thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd%40%3Cusers.activemq.apache.org%3E
Issue TrackingMailing ListThird Party Advisory
lists.apache.org / thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0%40%3Cdev.jmeter.apache.org%3E
Issue TrackingMailing ListThird Party Advisory
lists.debian.org / debian-lts-announce/2021/04/msg00002.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB
Mailing ListThird Party Advisory
security.netapp.com / advisory/ntap-20210430-0002
Third Party Advisory
debian.org / security/2021/dsa-5004
Mailing ListThird Party Advisory
oracle.com / security-alerts/cpujan2022.html
PatchVendor Advisory
oracle.com / /security-alerts/cpujul2021.html
Third Party Advisory
oracle.com / security-alerts/cpuoct2021.html
Third Party Advisory
x-stream.github.io / CVE-2021-21346.html
ExploitThird Party Advisory
x-stream.github.io / security.html
MitigationThird Party Advisory
x-stream.github.io / changes.html
Release NotesThird Party Advisory