CVE-2021-20156: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-6w2f-q3rq-jh8v
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CWE-347
Published
Advisory Summary

CVE-2021-20156 is a MODERATE security vulnerability vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not verify, or incorrectly verifies, the cryptographic signature for data.. Remediation is available in the latest vendor maintenance releases.

CVE-2021-20156 at a Glance

CVE Identifier CVE-2021-20156
GHSA Identifier GHSA-6w2f-q3rq-jh8v
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-347: Improper Verification of Cryptographic Signature
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2021-20156

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-2021-20156, 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-347: Improper Verification of Cryptographic Signature, where the product does not verify, or incorrectly verifies, the cryptographic signature for data. 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

Trendnet AC2600 TEW-827DRU version 2.08B01 contains an improper access control configuration that could allow for a malicious firmware update. It is possible to manually install firmware that may be malicious in nature as there does not appear to be any signature validation done to determine if it is from a known and trusted source. This includes firmware updates that are done via the automated "check for updates" in the admin interface. If an attacker is able to masquerade as the update server, the device will not verify that the firmware updates downloaded are legitimate.

References

NVD — CVE-2021-20156 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20156
Software Security Information SECURITY
https://www.tenable.com/security/research/tra-2021-54

Frequently Asked Questions

What is CVE-2021-20156?
CVE-2021-20156 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-347: Improper Verification of Cryptographic Signature.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-20156?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2021-20156?
CVE-2021-20156 is classified under CWE-347: Improper Verification of Cryptographic Signature (The product does not verify, or incorrectly verifies, the cryptographic signature for data.).
How can I check Maven dependencies for CVE-2021-20156?
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-6w2f-q3rq-jh8v",
  "modified" : "2022-01-08T00:00:35Z",
  "published" : "2021-12-31T00:00:33Z",
  "aliases" : [ "CVE-2021-20156" ],
  "details" : "Trendnet AC2600 TEW-827DRU version 2.08B01 contains an improper access control configuration that could allow for a malicious firmware update. It is possible to manually install firmware that may be malicious in nature as there does not appear to be any signature validation done to determine if it is from a known and trusted source. This includes firmware updates that are done via the automated \"check for updates\" in the admin interface. If an attacker is able to masquerade as the update server, the device will not verify that the firmware updates downloaded are legitimate.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-20156"
  }, {
    "type" : "WEB",
    "url" : "https://www.tenable.com/security/research/tra-2021-54"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-347" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2021-12-30T22:15:00Z"
  }
}