CVE-2021-21344: XStream is vulnerable to an Arbitrary Code Execution attack
Noroxi assessment
Priority: This week (action score 62/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 75.9% (FIRST EPSS); higher than 99.5% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: libxstream-java (Debian:12) 1.4.15-2; libxstream-java (Debian:9) 1.4.11.1-1+deb9u2; com.thoughtworks.xstream:xstream (Maven) 1.4.16.
- Severity is disputed: the assigning authority (CNA) scores it 5.3, NVD 9.8.
- Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Don’t wait for the next maintenance window. Upgrade to libxstream-java (Debian:12) 1.4.15-2; libxstream-java (Debian:9) 1.4.11.1-1+deb9u2; com.thoughtworks.xstream:xstream (Maven) 1.4.16 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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 to load and execute arbitrary code from a remote 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.
- Published
- Mar 23, 2021
- Updated
- Oct 7, 2026
- EPSS
- 75.9% · 99th percentile
- CWE
- CWE-434
Report tools
Action score
62
This week
Don’t wait for the next maintenance window.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 23 / 30 · 75.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 9.8
- CNA · GitHub_M
- 5.3
- 4.5 point gap
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| xstream | xstream | cpe:2.3:a:xstream:xstream |
| netapp | oncommand insight | cpe:2.3:a:netapp:oncommand_insight |
| apache | activemq | cpe:2.3:a:apache:activemq |
| apache | jmeter | cpe:2.3:a:apache:jmeter |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| oracle | banking enterprise default management | cpe:2.3:a:oracle:banking_enterprise_default_management |
| oracle | banking platform | cpe:2.3:a:oracle:banking_platform |
| oracle | banking virtual account management | cpe:2.3:a:oracle:banking_virtual_account_management |
| oracle | business activity monitoring | cpe:2.3:a:oracle:business_activity_monitoring |
| oracle | communications billing and revenue management elastic charging engine | cpe:2.3:a:oracle:communications_billing_and_revenue_management_elastic_charging_engine |
| oracle | communications policy management | cpe:2.3:a:oracle:communications_policy_management |
and 4 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apache activemqbefore 5.15.14
- apache activemq5.16.0
- apache activemq5.16.1
- apache jmeterbefore 5.5
- debian debian linux10.0
- debian debian linux11.0
- debian debian linux9.0
- fedoraproject fedora33
- fedoraproject fedora34
- fedoraproject fedora35
- netapp oncommand insightall versions
- oracle banking enterprise default management2.10.0
- oracle banking enterprise default management2.12.0
- oracle banking platform2.12.0
- oracle banking platform2.4.0
- oracle banking platform2.7.1
- oracle banking platform2.9.0
- oracle banking virtual account management14.2.0
- oracle banking virtual account management14.3.0
- oracle banking virtual account management14.5.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
x-stream xstream
- < 1.4.16affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libxstream-java | before 1.4.15-2 | 1.4.15-2 |
| Debian:9 | libxstream-java | before 1.4.11.1-1+deb9u2 | 1.4.11.1-1+deb9u2 |
| Maven | com.thoughtworks.xstream:xstream | before 1.4.16 | 1.4.16 |
| openSUSE:Leap 15.2 | xstream | before 1.4.16-lp152.2.6.1 | 1.4.16-lp152.2.6.1 |
| openSUSE:Leap 15.3 | xstream | before 1.4.16-3.8.1 | 1.4.16-3.8.1 |
| openSUSE:Tumbleweed | xstream | before 1.4.18-1.1 | 1.4.18-1.1 |
| Red Hat:enterprise_linux:7::client | xstream | before 0:1.3.1-13.el7_9 | 0:1.3.1-13.el7_9 |
| Red Hat:enterprise_linux:7::client | xstream-javadoc | before 0:1.3.1-13.el7_9 | 0:1.3.1-13.el7_9 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP2 | xstream | before 1.4.16-3.8.1 | 1.4.16-3.8.1 |
Same product
xstream: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-39144XStream is vulnerable to a Remote Command Execution attackKEV93Now
- CVE-2019-10173It was found that xstream API version 1.4.10 before 1.4.11 introduced a regression for a previous deserialization flaw.68This week
- CVE-2013-7285Xstream API versions up to 1.4.6 and version 1.4.10, if the security framework has not been initialized, may allow a remote attacker to run 64This week
Published before and after this one in the same product
- ← EarlierCVE-2021-21342Mar 23, 2021 · 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 51Plan
- ← EarlierCVE-2021-21343Mar 23, 2021 · XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling as long as the executing process has sufficient rights44Plan
- Later →CVE-2021-21345Mar 23, 2021 · XStream is vulnerable to a Remote Command Execution attack61This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:libxstream-java | 1.4.15-2 · Debian:12 | Package registry (OSV) |
| Maven:com.thoughtworks.xstream:xstream | 1.4.16 | Package registry (OSV) |
| opensuse:xstream | 1.4.16-lp152.2.6.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| red hat:xstream | 0:1.3.1-13.el7_9 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:xstream-javadoc | 0:1.3.1-13.el7_9 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:xstream | 1.4.16-3.8.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP2 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0989 · Dec 13, 2021(IBM Güvenlik Bildirimi)
- TR-21-0674 · Aug 25, 2021(IBM Güvenlik Bülteni Yayınladı)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-434 · Unrestricted Upload of File with Dangerous TypeCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (13 more)Show less
- github.com/x-stream/xstream/security/advisories/GHSA-59jw-jqf4-3wq3
- lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd%40%3Cusers.activemq.apache.org%3E
- lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0%40%3Cdev.jmeter.apache.org%3E
- lists.debian.org/debian-lts-announce/2021/04/msg00002.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/
- security.netapp.com/advisory/ntap-20210430-0002/
- www.debian.org/security/2021/dsa-5004
- www.oracle.com//security-alerts/cpujul2021.html
- www.oracle.com/security-alerts/cpujan2022.html
- www.oracle.com/security-alerts/cpuoct2021.html
- x-stream.github.io/security.html#workaround
Vendor advisories and official records. Exploit/PoC links are deliberately left out.