CVE-2020-2185: Ec2 Missing SSH Host Key Validation Vulnerability

MODERATE
Advisory Identifier: GHSA-q8qq-2p5p-rg44
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CVSS 5.6
CWE-300
Published
Advisory Summary

CVE-2020-2185 is a MODERATE (CVSS 5.6) missing ssh host key validation vulnerability (CWE-300: Channel Accessible by Non-Endpoint) affecting Ec2 libraries in the Maven ecosystem. The issue involves missing ssh host key validation in jenkins amazon ec2 plugin. Remediation is available by upgrading affected packages to version 1.50.2.

CVE-2020-2185 at a Glance

CVE Identifier CVE-2020-2185
GHSA Identifier GHSA-q8qq-2p5p-rg44
Severity MODERATE
CVSS v3.1 Base Score 5.6
CWE Classification CWE-300: Channel Accessible by Non-Endpoint
Affected Product Ec2
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L).

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

How to Fix CVE-2020-2185

To remediate this vulnerability, upgrade all affected Ec2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.jenkins-ci.plugins:ec2 fixed: 1.50.2 
<dependency>
    <groupId>org.jenkins-ci.plugins</groupId>
    <artifactId>ec2</artifactId>
    <version>1.50.2</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=org.jenkins-ci.plugins

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2020-2185, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.jenkins-ci.plugins

Analyze the terminal output to locate any version of Ec2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.50.2), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.jenkins-ci.plugins 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-300: Channel Accessible by Non-Endpoint, where the product does not adequately verify the identity of actors at both ends of a communication channel, or does not adequately ensure the integrity of the channel, in a way that allows the channel to be accessed or influenced by an actor that is not an endpoint. In Ec2, 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

Jenkins Amazon EC2 Plugin 1.50.1 and earlier does not use SSH host key validation when connecting to agents. This lack of validation could be abused using a man-in-the-middle attack to intercept these connections to build agents. Jenkins Amazon EC2 Plugin 1.50.2 provides strategies for performing host key validation for administrators to select the one that meets their security needs. It includes assistance for administrators to migrate to a new, more secure strategy. For more information see [the plugin documentation](https://github.com/jenkinsci/ec2-plugin/#securing-the-connection-to-unix-amis).

CVE-2020-2185 Affected Ec2 Versions

1 component(s)
Fixed Versions:
1.50.2
Product / Package Ecosystem Affected Versions Fixed Version
org.jenkins-ci.plugins:ec2
maven/org.jenkins-ci.plugins/ec2
Maven
< 1.50.2
1.50.2

References

NVD — CVE-2020-2185 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-2185
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/ec2-plugin/commit/4c9f03ae202e4730fd54eda40771fa4d3873e358
Ec2 Source Repository REPOSITORY
https://github.com/jenkinsci/ec2-plugin
Ec2 Security Information SECURITY
https://jenkins.io/security/advisory/2020-05-06/#SECURITY-381
Ec2 Security Information SECURITY
http://www.openwall.com/lists/oss-security/2020/05/06/3

Frequently Asked Questions

What is CVE-2020-2185?
CVE-2020-2185 is a security vulnerability in Ec2 involving Missing SSH host key validation in Jenkins Amazon EC2 Plugin under CWE-300: Channel Accessible by Non-Endpoint.
Which Ec2 versions are affected?
Affected versions include releases prior to 1.50.2 across affected packages: org.jenkins-ci.plugins:ec2.
What version fixes CVE-2020-2185?
Upgrading to 1.50.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ec2 affected?
Yes, org.jenkins-ci.plugins:ec2 is affected in releases prior to 1.50.2. Upgrade your dependency to 1.50.2 or later.
What is the CVSS score of CVE-2020-2185?
CVE-2020-2185 has a CVSS v3.1 base score of 5.6 (MODERATE) with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2020-2185?
CVE-2020-2185 is classified under CWE-300: Channel Accessible by Non-Endpoint (The product does not adequately verify the identity of actors at both ends of a communication channel, or does not adequately ensure the integrity of the channel, in a way that allows the channel to be accessed or influenced by an actor that is not an endpoint.).
How can I check Maven dependencies for CVE-2020-2185?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.jenkins-ci.plugins'. 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-q8qq-2p5p-rg44",
  "modified" : "2023-12-14T09:28:43Z",
  "published" : "2022-05-24T17:17:14Z",
  "aliases" : [ "CVE-2020-2185" ],
  "summary" : "Missing SSH host key validation in Jenkins Amazon EC2 Plugin",
  "details" : "Jenkins Amazon EC2 Plugin 1.50.1 and earlier does not use SSH host key validation when connecting to agents. This lack of validation could be abused using a man-in-the-middle attack to intercept these connections to build agents.\n\nJenkins Amazon EC2 Plugin 1.50.2 provides strategies for performing host key validation for administrators to select the one that meets their security needs. It includes assistance for administrators to migrate to a new, more secure strategy. For more information see [the plugin documentation](https://github.com/jenkinsci/ec2-plugin/#securing-the-connection-to-unix-amis).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.jenkins-ci.plugins:ec2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.50.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.50.1"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-2185"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/ec2-plugin/commit/4c9f03ae202e4730fd54eda40771fa4d3873e358"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jenkinsci/ec2-plugin"
  }, {
    "type" : "WEB",
    "url" : "https://jenkins.io/security/advisory/2020-05-06/#SECURITY-381"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2020/05/06/3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-300" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-12-16T22:55:37Z",
    "nvd_published_at" : "2020-05-06T13:15:00Z"
  }
}