CVE-2021-3642: Wildfly elytron Observable Discrepancy Vulnerability

MODERATE
Advisory Identifier: GHSA-5499-qjvh-6j7w
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CVSS 5.3
CWE-203
Published
Advisory Summary

CVE-2021-3642 is a MODERATE (CVSS 5.3) observable discrepancy vulnerability (CWE-203: Observable Discrepancy) affecting Wildfly elytron libraries in the Maven ecosystem. The issue involves observable discrepancy in wildfly elytron. Remediation is available by upgrading affected packages to version 1.10.14, 1.15.5, 1.16.1.

CVE-2021-3642 at a Glance

CVE Identifier CVE-2021-3642
GHSA Identifier GHSA-5499-qjvh-6j7w
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-203: Observable Discrepancy
Affected Product Wildfly elytron
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:H/PR:L/UI:N/S:U/C:H/I:N/A:N).

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

How to Fix CVE-2021-3642

To remediate this vulnerability, upgrade all affected Wildfly elytron 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.wildfly.security:wildfly-elytron fixed: 1.10.14 
<dependency>
    <groupId>org.wildfly.security</groupId>
    <artifactId>wildfly-elytron</artifactId>
    <version>1.10.14</version>
</dependency>
org.wildfly.security:wildfly-elytron fixed: 1.15.5 
<dependency>
    <groupId>org.wildfly.security</groupId>
    <artifactId>wildfly-elytron</artifactId>
    <version>1.15.5</version>
</dependency>
org.wildfly.security:wildfly-elytron fixed: 1.16.1 
<dependency>
    <groupId>org.wildfly.security</groupId>
    <artifactId>wildfly-elytron</artifactId>
    <version>1.16.1</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.wildfly.security

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-3642, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.wildfly.security

Analyze the terminal output to locate any version of Wildfly elytron in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.10.14), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.wildfly.security 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-203: Observable Discrepancy, where the product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor. In Wildfly elytron, 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 flaw was found in Wildfly Elytron where ScramServer may be susceptible to Timing Attack if enabled. The highest threat of this vulnerability is confidentiality. This flaw affectes Wildfly Elytron versions prior to 1.10.14.Final, prior to 1.15.5.Final and prior to 1.16.1.Final.

CVE-2021-3642 Affected Wildfly elytron Versions

3 component(s)
Fixed Versions:
1.10.141.15.51.16.1
Product / Package Ecosystem Affected Versions Fixed Version
org.wildfly.security:wildfly-elytron
maven/org.wildfly.security/wildfly-elytron
Maven
< 1.10.14
1.10.14
org.wildfly.security:wildfly-elytron
maven/org.wildfly.security/wildfly-elytron
Maven
≥ 1.11.0
< 1.15.5
1.15.5
org.wildfly.security:wildfly-elytron
maven/org.wildfly.security/wildfly-elytron
Maven
≥ 1.16.0
< 1.16.1
All 1 versions
1.16.0
1.16.1

References

NVD — CVE-2021-3642 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-3642
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1981407

Frequently Asked Questions

What is CVE-2021-3642?
CVE-2021-3642 is a security vulnerability in Wildfly elytron involving Observable Discrepancy in Wildfly Elytron under CWE-203: Observable Discrepancy.
Which Wildfly elytron versions are affected?
Affected versions include releases prior to 1.10.14, 1.15.5, 1.16.1 across affected packages: org.wildfly.security:wildfly-elytron.
What version fixes CVE-2021-3642?
Upgrading to 1.10.14, 1.15.5, 1.16.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is wildfly-elytron affected?
Yes, org.wildfly.security:wildfly-elytron is affected in releases prior to 1.10.14, 1.15.5, 1.16.1. Upgrade your dependency to 1.10.14, 1.15.5, 1.16.1 or later.
What is the CVSS score of CVE-2021-3642?
CVE-2021-3642 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2021-3642?
CVE-2021-3642 is classified under CWE-203: Observable Discrepancy (The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.).
How can I check Maven dependencies for CVE-2021-3642?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.wildfly.security'. 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-5499-qjvh-6j7w",
  "modified" : "2022-06-22T17:49:44Z",
  "published" : "2022-05-24T19:10:03Z",
  "aliases" : [ "CVE-2021-3642" ],
  "summary" : "Observable Discrepancy in Wildfly Elytron",
  "details" : "A flaw was found in Wildfly Elytron where ScramServer may be susceptible to Timing Attack if enabled. The highest threat of this vulnerability is confidentiality. This flaw affectes Wildfly Elytron versions prior to 1.10.14.Final, prior to 1.15.5.Final and prior to 1.16.1.Final.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.wildfly.security:wildfly-elytron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.10.14"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.10.13"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.wildfly.security:wildfly-elytron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.11.0"
      }, {
        "fixed" : "1.15.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.15.4"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.wildfly.security:wildfly-elytron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.16.0"
      }, {
        "fixed" : "1.16.1"
      } ]
    } ],
    "versions" : [ "1.16.0" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3642"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1981407"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-203" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-22T17:49:44Z",
    "nvd_published_at" : "2021-08-05T21:15:00Z"
  }
}