CVE-2020-19676: Nacos common Incorrect Access Control Vulnerability

MODERATE
Advisory Identifier: GHSA-qf76-pr7x-h7r4
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CVSS 5.3
CWE-200
Published
Advisory Summary

CVE-2020-19676 is a MODERATE (CVSS 5.3) incorrect access control vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Nacos common libraries in the Maven ecosystem. The issue involves incorrect access control in nacos. Remediation is available by upgrading affected packages to version 1.2.0.

CVE-2020-19676 at a Glance

CVE Identifier CVE-2020-19676
GHSA Identifier GHSA-qf76-pr7x-h7r4
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Nacos common
Package Ecosystem Maven
Published Date
Last Updated

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:L/PR:N/UI:N/S:U/C:L/I:N/A:N).

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

How to Fix CVE-2020-19676

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: 1.2.0 
<dependency>
    <groupId>com.alibaba.nacos</groupId>
    <artifactId>nacos-common</artifactId>
    <version>1.2.0</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-2020-19676, 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 1.2.0), 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-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. 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

Nacos 1.1.4 is affected by: Incorrect Access Control. An environment can be set up locally to get the service details interface. Then other Nacos service names can be accessed through the service list interface. Service details can then be accessed when not logged in. (detail:https://github.com/alibaba/nacos/issues/2284)

CVE-2020-19676 Affected Nacos common Versions

1 component(s)
Fixed Versions:
1.2.0
Product / Package Ecosystem Affected Versions Fixed Version
com.alibaba.nacos:nacos-common
maven/com.alibaba.nacos/nacos-common
Maven
< 1.2.0
1.2.0

References

NVD — CVE-2020-19676 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-19676
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos/issues/1105
Nacos common Source Repository REPOSITORY
https://github.com/alibaba/nacos/issues/2284
Nacos common Release RELEASE
https://github.com/alibaba/nacos/releases/tag/1.2.0

Frequently Asked Questions

What is CVE-2020-19676?
CVE-2020-19676 is a security vulnerability in Nacos common involving Incorrect Access Control in Nacos under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Nacos common versions are affected?
Affected versions include releases prior to 1.2.0 across affected packages: com.alibaba.nacos:nacos-common.
What version fixes CVE-2020-19676?
Upgrading to 1.2.0 (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 1.2.0. Upgrade your dependency to 1.2.0 or later.
What is the CVSS score of CVE-2020-19676?
CVE-2020-19676 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2020-19676?
CVE-2020-19676 is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.).
How can I check Maven dependencies for CVE-2020-19676?
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-qf76-pr7x-h7r4",
  "modified" : "2021-04-22T23:02:07Z",
  "published" : "2021-08-02T16:38:01Z",
  "aliases" : [ "CVE-2020-19676" ],
  "summary" : "Incorrect Access Control in Nacos",
  "details" : "Nacos 1.1.4 is affected by: Incorrect Access Control. An environment can be set up locally to get the service details interface. Then other Nacos service names can be accessed through the service list interface. Service details can then be accessed when not logged in. (detail:https://github.com/alibaba/nacos/issues/2284)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.alibaba.nacos:nacos-common"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-19676"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/issues/1105"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/issues/2284"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/alibaba/nacos/releases/tag/1.2.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-22T23:02:07Z",
    "nvd_published_at" : "2020-09-30T18:15:00Z"
  }
}