CVE-2021-41862: Aviator Expression Injection Vulnerability

CRITICAL

Advisory Identifier: GHSA-xpv2-8ppj-79hh

CVSS 9.8

Published 2021-10-04

Advisory Summary

CVE-2021-41862 is a CRITICAL (CVSS 9.8) expression injection vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')) affecting Aviator libraries in the Maven ecosystem. The issue involves expression injection in aviatorscript. Remediation is available in the latest vendor maintenance releases.

CVE-2021-41862 at a Glance

CVE Identifier CVE-2021-41862

GHSA Identifier GHSA-xpv2-8ppj-79hh

Severity CRITICAL

CVSS v3.1 Base Score 9.8

CWE Classification CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Affected Product Aviator

Package Ecosystem Maven

Published Date 2021-10-04

Last Updated 2024-02-20

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)

Integrity High (I:H)

Availability High (A:H)

How to Fix CVE-2021-41862

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

com.googlecode.aviator:aviator fixed: Latest secure release

<dependency>
    <groupId>com.googlecode.aviator</groupId>
    <artifactId>aviator</artifactId>
    <version>Latest secure release</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=com.googlecode.aviator

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-41862, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.googlecode.aviator

Analyze the terminal output to locate any version of Aviator 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 -Dincludes=com.googlecode.aviator 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-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection'), where the product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. In Aviator, 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

AviatorScript through 5.2.7 allows code execution via an expression that is encoded with Byte Code Engineering Library (BCEL).

CVE-2021-41862 Affected Aviator Versions

1 component(s)

Product / Package	Ecosystem	Affected Versions	Fixed Version
com.googlecode.aviator:aviator maven/com.googlecode.aviator/aviator	Maven	≥ 5.2.1 ≤ 5.2.7

References

NVD — CVE-2021-41862 NVD

https://nvd.nist.gov/vuln/detail/CVE-2021-41862

Aviator Source Repository REPOSITORY

https://github.com/killme2008/aviatorscript/issues/421

Aviator Source Repository REPOSITORY

https://github.com/killme2008/aviatorscript

Frequently Asked Questions

What is CVE-2021-41862?

CVE-2021-41862 is a security vulnerability in Aviator involving Expression injection in AviatorScript under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection').

Which Aviator versions are affected?

Affected versions include releases prior to current release patches across affected packages: com.googlecode.aviator:aviator.

What version fixes CVE-2021-41862?

Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.

Is aviator affected?

Yes, com.googlecode.aviator:aviator is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.

What is the CVSS score of CVE-2021-41862?

CVE-2021-41862 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

What CWE is associated with CVE-2021-41862?

CVE-2021-41862 is classified under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.).

How can I check Maven dependencies for CVE-2021-41862?

Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.googlecode.aviator'. 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-xpv2-8ppj-79hh",
  "modified" : "2024-02-20T20:07:33Z",
  "published" : "2021-10-04T20:14:31Z",
  "aliases" : [ "CVE-2021-41862" ],
  "summary" : "Expression injection in AviatorScript",
  "details" : "AviatorScript through 5.2.7 allows code execution via an expression that is encoded with Byte Code Engineering Library (BCEL).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.googlecode.aviator:aviator"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.2.1"
      }, {
        "last_affected" : "5.2.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41862"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/killme2008/aviatorscript/issues/421"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/killme2008/aviatorscript"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-74" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-04T16:58:38Z",
    "nvd_published_at" : "2021-10-02T00:15:00Z"
  }
}

CVSS V3

9.8 CRITICAL