CVE-2021-42020: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-g9pm-vppm-577q
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CVSS 7.5
CWE-754
Published
Advisory Summary

CVE-2021-42020 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-754: Improper Check for Unusual or Exceptional Conditions) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.. Remediation is available in the latest vendor maintenance releases.

CVE-2021-42020 at a Glance

CVE Identifier CVE-2021-42020
GHSA Identifier GHSA-g9pm-vppm-577q
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-754: Improper Check for Unusual or Exceptional Conditions
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/I:N/A:H).

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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-42020

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

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

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-42020, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

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

Note: The mvn dependency:tree 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-754: Improper Check for Unusual or Exceptional Conditions, where the product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. In Software, 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 vulnerability has been identified in RUGGEDCOM ROS M2100 (All versions < V5.6.0), RUGGEDCOM ROS RMC8388 devices (All versions < V5.6.0), RUGGEDCOM ROS RS416v2 (All versions < V5.6.0), RUGGEDCOM ROS RS900G (All versions < V5.6.0), RUGGEDCOM ROS RS900G (32M) (All versions < V5.6.0), RUGGEDCOM ROS RSG2100 (32M) V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2100P (All versions < V5.6.0), RUGGEDCOM ROS RSG2100P (32M) V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2288 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2300 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2300P V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2488 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG900 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG920P V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSL910 (All versions < V5.6.0), RUGGEDCOM ROS RST2228 (All versions < V5.6.0), RUGGEDCOM ROS RST916C (All versions < V5.6.0), RUGGEDCOM ROS RST916P (All versions < V5.6.0). The third-party component in its TFTP functionality fails to check for null terminations in file names. If an attacker were to exploit this, it could result in data corruption, and possibly a hard-fault of the application.

References

NVD — CVE-2021-42020 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42020
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-256353.html
cert-portal.siemens.com/productcert/pdf/ssa... WEB
https://cert-portal.siemens.com/productcert/pdf/ssa-256353.pdf

Frequently Asked Questions

What is CVE-2021-42020?
CVE-2021-42020 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-754: Improper Check for Unusual or Exceptional Conditions.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-42020?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2021-42020?
CVE-2021-42020 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-42020?
CVE-2021-42020 is classified under CWE-754: Improper Check for Unusual or Exceptional Conditions (The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.).
How can I check Maven dependencies for CVE-2021-42020?
Run the dependency tree command: 'mvn dependency:tree'. 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-g9pm-vppm-577q",
  "modified" : "2025-08-12T12:30:32Z",
  "published" : "2022-03-09T00:00:45Z",
  "aliases" : [ "CVE-2021-42020" ],
  "details" : "A vulnerability has been identified in RUGGEDCOM ROS M2100 (All versions < V5.6.0), RUGGEDCOM ROS RMC8388 devices (All versions < V5.6.0), RUGGEDCOM ROS RS416v2 (All versions < V5.6.0), RUGGEDCOM ROS RS900G (All versions < V5.6.0), RUGGEDCOM ROS RS900G (32M) (All versions < V5.6.0), RUGGEDCOM ROS RSG2100 (32M) V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2100P (All versions < V5.6.0), RUGGEDCOM ROS RSG2100P (32M) V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2288 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2300 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2300P V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG2488 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG900 V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSG920P V5.X (All versions < V5.6.0), RUGGEDCOM ROS RSL910 (All versions < V5.6.0), RUGGEDCOM ROS RST2228 (All versions < V5.6.0), RUGGEDCOM ROS RST916C (All versions < V5.6.0), RUGGEDCOM ROS RST916P (All versions < V5.6.0). The third-party component in its TFTP functionality fails to check for null terminations in file names. If an attacker were to exploit this, it could result in data corruption, and possibly a hard-fault of the application.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-42020"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-256353.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-256353.pdf"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-754" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2022-03-08T12:15:00Z"
  }
}