CVE-2021-44667: Nacos common Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-4gr7-qw2q-jxh6
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CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2021-44667 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Nacos common libraries in the Maven ecosystem. The issue involves cross-site scripting in nacos. Remediation is available by upgrading affected packages to version 2.1.0-BETA, 1.4.5.

CVE-2021-44667 at a Glance

CVE Identifier CVE-2021-44667
GHSA Identifier GHSA-4gr7-qw2q-jxh6
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Nacos common
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.1

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2021-44667

To remediate this vulnerability, upgrade all affected Nacos common 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.alibaba.nacos:nacos-common fixed: 2.1.0-BETA 
<dependency>
    <groupId>com.alibaba.nacos</groupId>
    <artifactId>nacos-common</artifactId>
    <version>2.1.0-BETA</version>
</dependency>
com.alibaba.nacos:nacos-common fixed: 1.4.5 
<dependency>
    <groupId>com.alibaba.nacos</groupId>
    <artifactId>nacos-common</artifactId>
    <version>1.4.5</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.alibaba.nacos

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-44667, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.alibaba.nacos

Analyze the terminal output to locate any version of Nacos common in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.1.0-BETA), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.alibaba.nacos 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Nacos common, 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

A Cross Site Scripting (XSS) vulnerability exists in Nacos prior to 1.4.5 and 2.1.0-BETA in auth/users via the (1) pageSize and (2) pageNo parameters.

CVE-2021-44667 Affected Nacos common Versions

2 component(s)
Fixed Versions:
2.1.0-BETA1.4.5
Product / Package Ecosystem Affected Versions Fixed Version
com.alibaba.nacos:nacos-common
maven/com.alibaba.nacos/nacos-common
Maven
≥ 2.0.0-ALPHA.1
< 2.1.0-BETA
2.1.0-BETA
com.alibaba.nacos:nacos-common
maven/com.alibaba.nacos/nacos-common
Maven
< 1.4.5
1.4.5

References

NVD — CVE-2021-44667 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-44667
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos/issues/7359
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos/pull/7364
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos/pull/8980
Security Fix Commit FIX COMMIT
https://github.com/alibaba/nacos/commit/cd6d7e33b94f24814701f3faf8b632e5e85444c5
Security Fix Commit FIX COMMIT
https://github.com/alibaba/nacos/commit/d062fcafad0acd01673d404319526415a4af372b
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos

Frequently Asked Questions

What is CVE-2021-44667?
CVE-2021-44667 is a security vulnerability in Nacos common involving Cross-site Scripting in Nacos under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Nacos common versions are affected?
Affected versions include releases prior to 2.1.0-BETA, 1.4.5 across affected packages: com.alibaba.nacos:nacos-common.
What version fixes CVE-2021-44667?
Upgrading to 2.1.0-BETA, 1.4.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nacos-common affected?
Yes, com.alibaba.nacos:nacos-common is affected in releases prior to 2.1.0-BETA, 1.4.5. Upgrade your dependency to 2.1.0-BETA, 1.4.5 or later.
What is the CVSS score of CVE-2021-44667?
CVE-2021-44667 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2021-44667?
CVE-2021-44667 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2021-44667?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.alibaba.nacos'. 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-4gr7-qw2q-jxh6",
  "modified" : "2025-07-18T18:08:06Z",
  "published" : "2022-03-12T00:00:27Z",
  "aliases" : [ "CVE-2021-44667" ],
  "summary" : "Cross-site Scripting in Nacos",
  "details" : "A Cross Site Scripting (XSS) vulnerability exists in Nacos prior to 1.4.5 and 2.1.0-BETA in auth/users via the (1) pageSize and (2) pageNo parameters.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.alibaba.nacos:nacos-common"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0-ALPHA.1"
      }, {
        "fixed" : "2.1.0-BETA"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.alibaba.nacos:nacos-common"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-44667"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/issues/7359"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/pull/7364"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/pull/8980"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/commit/cd6d7e33b94f24814701f3faf8b632e5e85444c5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/commit/d062fcafad0acd01673d404319526415a4af372b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/alibaba/nacos"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-03-14T23:25:35Z",
    "nvd_published_at" : "2022-03-11T19:15:00Z"
  }
}