NVD / CVE Program· CNA GitHub_M

CVE-2021-39152: A Server-Side Forgery Request vulnerability in XStream via HashMap unmarshaling

Noroxi assessment

Priority: Monitor (action score 37/100)

A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Public proof-of-concept code exists (Exploit-DB / GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 11.3% (FIRST EPSS); higher than 95.9% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: libxstream-java (Debian:10) 1.4.11.1-1+deb10u3; libxstream-java (Debian:11) 1.4.15-3+deb11u1; libxstream-java (Debian:12) 1.4.18-1.
Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to libxstream-java (Debian:10) 1.4.11.1-1+deb10u3; libxstream-java (Debian:11) 1.4.15-3+deb11u1; libxstream-java (Debian:12) 1.4.18-1 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 simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream with a Java runtime version 14 to 8. 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](https://x-stream.github.io/security.html#framework), you will have to use at least version 1.4.18.

HighCVSS 8.5 · v3.1—Proof of concept Fix available

Deserialization

Published: Aug 23, 2021
Updated: Oct 7, 2026
EPSS: 11.3% · 95th percentile
CWE: CWE-502

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 3 / 30 · 11.3%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 8.5
CNA · GitHub_M: 8.5; agree

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
Proof of concept exists, no weaponized module
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.

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Affected 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
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora
debian	debian linux	cpe:2.3:o:debian:debian_linux
netapp	snapmanager	cpe:2.3:a:netapp:snapmanager
oracle	business activity monitoring	cpe:2.3:a:oracle:business_activity_monitoring
oracle	commerce guided search	cpe:2.3:a:oracle:commerce_guided_search
oracle	communications billing and revenue management elastic charging engine	cpe:2.3:a:oracle:communications_billing_and_revenue_management_elastic_charging_engine
oracle	communications cloud native core automated test suite	cpe:2.3:a:oracle:communications_cloud_native_core_automated_test_suite
oracle	communications cloud native core binding support function	cpe:2.3:a:oracle:communications_cloud_native_core_binding_support_function
oracle	communications cloud native core policy	cpe:2.3:a:oracle:communications_cloud_native_core_policy
oracle	communications unified inventory management	cpe:2.3:a:oracle:communications_unified_inventory_management
oracle	retail xstore point of service	cpe:2.3:a:oracle:retail_xstore_point_of_service

and 3 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

debian debian linux10.0
debian debian linux11.0
debian debian linux9.0
fedoraproject fedora33
fedoraproject fedora34
fedoraproject fedora35
netapp snapmanagerall versions
oracle business activity monitoring12.2.1.4.0
oracle commerce guided search11.3.2
oracle communications billing and revenue management elastic charging engine11.3
oracle communications billing and revenue management elastic charging engine12.0
oracle communications cloud native core automated test suite1.9.0
oracle communications cloud native core binding support function1.10.0
oracle communications cloud native core policy1.14.0
oracle communications unified inventory management7.3.4
oracle communications unified inventory management7.3.5
oracle communications unified inventory management7.4.0
oracle communications unified inventory management7.4.1
oracle communications unified inventory management7.4.2
oracle retail xstore point of service16.0.6

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
- < 1.4.18affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:10	libxstream-java	before 1.4.11.1-1+deb10u3	1.4.11.1-1+deb10u3
Debian:11	libxstream-java	before 1.4.15-3+deb11u1	1.4.15-3+deb11u1
Debian:12	libxstream-java	before 1.4.18-1	1.4.18-1
Debian:9	libxstream-java	before 1.4.11.1-1+deb9u4	1.4.11.1-1+deb9u4
Maven	com.thoughtworks.xstream:xstream	before 1.4.18	1.4.18
openSUSE:Leap 15.2	xstream	before 1.4.18-lp152.2.12.1	1.4.18-lp152.2.12.1
openSUSE:Leap 15.3	xstream	before 1.4.18-3.14.1	1.4.18-3.14.1
Red Hat:enterprise_linux:7::client	xstream	before 0:1.3.1-16.el7_9	0:1.3.1-16.el7_9
Red Hat:enterprise_linux:7::client	xstream-javadoc	before 0:1.3.1-16.el7_9	0:1.3.1-16.el7_9
SUSE:Linux Enterprise Module for Development Tools 15 SP2	xstream	before 1.4.18-3.14.1	1.4.18-3.14.1

Same product

xstream: all records

Other highest-scoring records for the same primary product.

CVE-2021-39144XStream is vulnerable to a Remote Command Execution attackKEV
93Now
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-2021-39140Aug 23, 2021 · XStream can cause a Denial of Service
27Monitor
← EarlierCVE-2021-39150Aug 23, 2021 · A Server-Side Forgery Request vulnerability in XStream via PriorityQueue unmarshaling
35Monitor
Later →CVE-2021-43859Feb 1, 2022 · Denial of Service by injecting highly recursive collections or maps in XStream
32Monitor

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	1.4.18-1 · Debian:12	Package registry (OSV)
Maven:com.thoughtworks.xstream:xstream	1.4.18	Package registry (OSV)
opensuse:xstream	1.4.18-lp152.2.12.1 · openSUSE:Leap 15.2	Package registry (OSV)
red hat:xstream	0:1.3.1-16.el7_9 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:xstream-javadoc	0:1.3.1-16.el7_9 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
suse:xstream	1.4.18-3.14.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP2	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Nuclei detection template ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2021-39152	—

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 researchers

Finders, 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-22-0143 · Feb 15, 2022(RedHat Güvenlik Güncellemesi)
TR-21-0989 · Dec 13, 2021(IBM Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Changed
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))