CVE-2020-27867: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-9xcx-66r3-hp2h
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CWE-77
Published
Advisory Summary

CVE-2020-27867 is a HIGH security vulnerability vulnerability (CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.. Remediation is available in the latest vendor maintenance releases.

CVE-2020-27867 at a Glance

CVE Identifier CVE-2020-27867
GHSA Identifier GHSA-9xcx-66r3-hp2h
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2020-27867

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-2020-27867, 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-77: Improper Neutralization of Special Elements used in a Command ('Command Injection'), where the product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. 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

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, Nighthawk AC2100, and Nighthawk AC2400 firmware version 1.2.0.62_1.0.1 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the mini_httpd service, which listens on TCP port 80 by default. When parsing the funjsq_access_token parameter, the process does not properly validate a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-11653.

References

NVD — CVE-2020-27867 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-27867
Software Security Information SECURITY
https://kb.netgear.com/000062641/Security-Advisory-for-Password-Recovery-Vulnerabilities-on-Some-Routers
www.zerodayinitiative.com/advisories/zdi-20-1... WEB
https://www.zerodayinitiative.com/advisories/ZDI-20-1423

Frequently Asked Questions

What is CVE-2020-27867?
CVE-2020-27867 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2020-27867?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2020-27867?
CVE-2020-27867 is classified under CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection') (The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.).
How can I check Maven dependencies for CVE-2020-27867?
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-9xcx-66r3-hp2h",
  "modified" : "2022-05-24T17:42:02Z",
  "published" : "2022-05-24T17:42:02Z",
  "aliases" : [ "CVE-2020-27867" ],
  "details" : "This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6020, R6080, R6120, R6220, R6260, R6700v2, R6800, R6900v2, R7450, JNR3210, WNR2020, Nighthawk AC2100, and Nighthawk AC2400 firmware version 1.2.0.62_1.0.1 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the mini_httpd service, which listens on TCP port 80 by default. When parsing the funjsq_access_token parameter, the process does not properly validate a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-11653.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-27867"
  }, {
    "type" : "WEB",
    "url" : "https://kb.netgear.com/000062641/Security-Advisory-for-Password-Recovery-Vulnerabilities-on-Some-Routers"
  }, {
    "type" : "WEB",
    "url" : "https://www.zerodayinitiative.com/advisories/ZDI-20-1423"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-77" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2021-02-12T00:15:00Z"
  }
}