CVE-2021-21342: Xstream Remote Code Execution Vulnerability

Q: What is CVE-2021-21342?

CVE-2021-21342 is a security vulnerability in Xstream involving 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 the local host under CWE-502: Deserialization of Untrusted Data.

Q: Which Xstream versions are affected?

Affected versions include releases prior to 1.4.16 across affected packages: com.thoughtworks.xstream:xstream.

Q: What version fixes CVE-2021-21342?

Upgrading to 1.4.16 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is xstream affected?

Yes, com.thoughtworks.xstream:xstream is affected in releases prior to 1.4.16. Upgrade your dependency to 1.4.16 or later.

Q: What is the CVSS score of CVE-2021-21342?

CVE-2021-21342 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.

Q: What CWE is associated with CVE-2021-21342?

CVE-2021-21342 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).

Q: How can I check Maven dependencies for CVE-2021-21342?

Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.thoughtworks.xstream'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

MODERATE

Advisory Identifier: GHSA-hvv8-336g-rx3m

CVSS 5.3

CWE-502 CWE-918

Published 2021-03-22

Advisory Summary

CVE-2021-21342 is a MODERATE (CVSS 5.3) remote code execution vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Xstream libraries in the Maven ecosystem. The issue involves 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 the local host. Remediation is available by upgrading affected packages to version 1.4.16.

CVE-2021-21342 at a Glance

CVE Identifier CVE-2021-21342

GHSA Identifier GHSA-hvv8-336g-rx3m

Severity MODERATE

CVSS v3.1 Base Score 5.3

CWE Classification CWE-502: Deserialization of Untrusted Data

Affected Product Xstream

Package Ecosystem Maven

Published Date 2021-03-22

Last Updated 2023-03-09

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)

Attack Complexity High (AC:H)

Privileges Required None (PR:N)

User Interaction Required (UI:R)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity High (I:H)

Availability None (A:N)

How to Fix CVE-2021-21342

To remediate this vulnerability, upgrade all affected Xstream dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

com.thoughtworks.xstream:xstream fixed: 1.4.16

<dependency>
    <groupId>com.thoughtworks.xstream</groupId>
    <artifactId>xstream</artifactId>
    <version>1.4.16</version>
</dependency>

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

mvn dependency:tree -Dincludes=com.thoughtworks.xstream

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-21342, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.thoughtworks.xstream

Analyze the terminal output to locate any version of Xstream in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.16), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.thoughtworks.xstream command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Xstream, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The processed stream at unmarshalling time contains type information to recreate the formerly written objects. XStream creates therefore new instances based on these type information. An attacker can manipulate the processed input stream and replace or inject objects, that result in a server-side forgery request. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. ### Patches 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 1.4.16 ### Workarounds See [workarounds](https://x-stream.github.io/security.html#workaround) for the different versions covering all CVEs. ### References See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for [CVE-2021-21342](https://x-stream.github.io/CVE-2021-21342.html). ### Credits 钟潦贵 (Liaogui Zhong) found and reported the issue to XStream and provided the required information to reproduce it. ### For more information If you have any questions or comments about this advisory: * Open an issue in [XStream](https://github.com/x-stream/xstream/issues) * Contact us at [XStream Google Group](https://groups.google.com/group/xstream-user)

CVE-2021-21342 Affected Xstream Versions

1 component(s)

Fixed Versions:

1.4.16

Product / Package	Ecosystem	Affected Versions	Fixed Version
com.thoughtworks.xstream:xstream maven/com.thoughtworks.xstream/xstream	Maven	< 1.4.16	1.4.16

References

GitHub Advisory / Wiki ADVISORY

https://github.com/x-stream/xstream/security/advisories/GHSA-hvv8-336g-rx3m

NVD — CVE-2021-21342 NVD

https://nvd.nist.gov/vuln/detail/CVE-2021-21342

Xstream Source Repository REPOSITORY

https://github.com/x-stream/xstream

lists.apache.org/thread.html/r8244fd... WEB

https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd@%3Cusers.activemq.apache.org%3E

lists.apache.org/thread.html/r9ac71b... WEB

https://lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0@%3Cdev.jmeter.apache.org%3E

lists.debian.org/debian-lts-announce... WEB

https://lists.debian.org/debian-lts-announce/2021/04/msg00002.html

lists.fedoraproject.org/archives/list/packa... WEB

https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP

lists.fedoraproject.org/archives/list/packa... WEB

https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7

lists.fedoraproject.org/archives/list/packa... WEB

https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB

Xstream Security Information SECURITY

https://security.netapp.com/advisory/ntap-20210430-0002

Xstream Security Information SECURITY

https://www.debian.org/security/2021/dsa-5004

Xstream Security Information SECURITY

https://www.oracle.com//security-alerts/cpujul2021.html

Xstream Security Information SECURITY

https://www.oracle.com/security-alerts/cpujan2022.html

Xstream Security Information SECURITY

https://www.oracle.com/security-alerts/cpuoct2021.html

x-stream.github.io/cve-2021-21342.html WEB

https://x-stream.github.io/CVE-2021-21342.html

Xstream Security Information SECURITY

https://x-stream.github.io/security.html#workaround

x-stream.github.io/changes.html WEB

http://x-stream.github.io/changes.html#1.4.16

Frequently Asked Questions

What is CVE-2021-21342?

CVE-2021-21342 is a security vulnerability in Xstream involving 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 the local host under CWE-502: Deserialization of Untrusted Data.

Which Xstream versions are affected?

Affected versions include releases prior to 1.4.16 across affected packages: com.thoughtworks.xstream:xstream.

What version fixes CVE-2021-21342?

Upgrading to 1.4.16 (or the latest patched release for your respective branch) resolves the vulnerability.

Is xstream affected?

Yes, com.thoughtworks.xstream:xstream is affected in releases prior to 1.4.16. Upgrade your dependency to 1.4.16 or later.

What is the CVSS score of CVE-2021-21342?

CVE-2021-21342 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.

What CWE is associated with CVE-2021-21342?

CVE-2021-21342 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).

How can I check Maven dependencies for CVE-2021-21342?

Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.thoughtworks.xstream'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

Machine-readable OSV JSON OSV v1.5 Schema

Normalized schema output

View Raw JSON

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hvv8-336g-rx3m",
  "modified" : "2023-03-09T21:21:55Z",
  "published" : "2021-03-22T23:28:01Z",
  "aliases" : [ "CVE-2021-21342" ],
  "summary" : "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 the local host",
  "details" : "### Impact\nThe processed stream at unmarshalling time contains type information to recreate the formerly written objects. XStream creates therefore new instances based on these type information.  An attacker can manipulate the processed input stream and replace or inject objects, that result in a server-side forgery request. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types.\n\n### Patches\nIf 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 1.4.16\n\n### Workarounds\nSee [workarounds](https://x-stream.github.io/security.html#workaround) for the different versions covering all CVEs.\n\n### References\nSee full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for [CVE-2021-21342](https://x-stream.github.io/CVE-2021-21342.html).\n\n### Credits\n钟潦贵 (Liaogui Zhong) found and reported the issue to XStream and provided the required information to reproduce it.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [XStream](https://github.com/x-stream/xstream/issues)\n* Contact us at [XStream Google Group](https://groups.google.com/group/xstream-user)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.thoughtworks.xstream:xstream"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.16"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/x-stream/xstream/security/advisories/GHSA-hvv8-336g-rx3m"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21342"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/x-stream/xstream"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd@%3Cusers.activemq.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r9ac71b047767205aa22e3a08cb33f3e0586de6b2fac48b425c6e16b0@%3Cdev.jmeter.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2021/04/msg00002.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20210430-0002"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2021/dsa-5004"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com//security-alerts/cpujul2021.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuoct2021.html"
  }, {
    "type" : "WEB",
    "url" : "https://x-stream.github.io/CVE-2021-21342.html"
  }, {
    "type" : "WEB",
    "url" : "https://x-stream.github.io/security.html#workaround"
  }, {
    "type" : "WEB",
    "url" : "http://x-stream.github.io/changes.html#1.4.16"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502", "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-03-22T23:23:33Z",
    "nvd_published_at" : "2021-03-23T00:15:00Z"
  }
}

CVSS V3

5.3 MODERATE

Attack Vector Network (AV:N)

Attack Complexity High (AC:H)

Privileges Required None (PR:N)

User Interaction Required (UI:R)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity High (I:H)

Availability None (A:N)

Vector String

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

Advisory Metadata

Source ID: GHSA-hvv8-336g-rx3m
Schema Version: 1.4.0
Published: 2021-03-22 23:28
Last Modified: 2023-03-09 21:21
Database Record File: advisories/github-reviewed/2021/03/GHSA-hvv8-336g-rx3m/GHSA-hvv8-336g-rx3m.json