CVE-2021-4166: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-5q95-22v3-59qw
CVSS 7.1
CWE-125
Published
Advisory Summary

CVE-2021-4166 is a HIGH (CVSS 7.1) security vulnerability vulnerability (CWE-125: Out-of-bounds Read) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product reads data past the end, or before the beginning, of the intended buffer.. Remediation is available in the latest vendor maintenance releases.

CVE-2021-4166 at a Glance

CVE Identifier CVE-2021-4166
GHSA Identifier GHSA-5q95-22v3-59qw
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-125: Out-of-bounds Read
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H).

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

How to Fix CVE-2021-4166

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-2021-4166, 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-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. 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

vim is vulnerable to Out-of-bounds Read

References

NVD — CVE-2021-4166 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-4166
Security Fix Commit FIX COMMIT
https://github.com/vim/vim/commit/6f98371532fcff911b462d51bc64f2ce8a6ae682
huntr.dev/bounties/229df5dd-5... WEB
https://huntr.dev/bounties/229df5dd-5507-44e9-832c-c70364bdf035
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2EY2VFBU3YGGWI5BW4XKT3F37MYGEQUD
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3FH2J57GDA2WMBS6J56F6QQRA6BXQQFZ
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2EY2VFBU3YGGWI5BW4XKT3F37MYGEQUD
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3FH2J57GDA2WMBS6J56F6QQRA6BXQQFZ
Software Security Information SECURITY
https://security.gentoo.org/glsa/202208-32
support.apple.com/kb/ht213183 WEB
https://support.apple.com/kb/HT213183
support.apple.com/kb/ht213256 WEB
https://support.apple.com/kb/HT213256
support.apple.com/kb/ht213343 WEB
https://support.apple.com/kb/HT213343
seclists.org/fulldisclosure/2022... WEB
http://seclists.org/fulldisclosure/2022/Jul/14
seclists.org/fulldisclosure/2022... WEB
http://seclists.org/fulldisclosure/2022/Mar/29
seclists.org/fulldisclosure/2022... WEB
http://seclists.org/fulldisclosure/2022/May/35
Software Security Information SECURITY
http://www.openwall.com/lists/oss-security/2022/01/15/1

Frequently Asked Questions

What is CVE-2021-4166?
CVE-2021-4166 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-125: Out-of-bounds Read.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-4166?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2021-4166?
CVE-2021-4166 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.
What CWE is associated with CVE-2021-4166?
CVE-2021-4166 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check Maven dependencies for CVE-2021-4166?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5q95-22v3-59qw",
  "modified" : "2026-10-08T21:32:51Z",
  "published" : "2021-12-26T00:00:47Z",
  "aliases" : [ "CVE-2021-4166" ],
  "details" : "vim is vulnerable to Out-of-bounds Read",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-4166"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vim/vim/commit/6f98371532fcff911b462d51bc64f2ce8a6ae682"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.dev/bounties/229df5dd-5507-44e9-832c-c70364bdf035"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2EY2VFBU3YGGWI5BW4XKT3F37MYGEQUD"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3FH2J57GDA2WMBS6J56F6QQRA6BXQQFZ"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2EY2VFBU3YGGWI5BW4XKT3F37MYGEQUD"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3FH2J57GDA2WMBS6J56F6QQRA6BXQQFZ"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202208-32"
  }, {
    "type" : "WEB",
    "url" : "https://support.apple.com/kb/HT213183"
  }, {
    "type" : "WEB",
    "url" : "https://support.apple.com/kb/HT213256"
  }, {
    "type" : "WEB",
    "url" : "https://support.apple.com/kb/HT213343"
  }, {
    "type" : "WEB",
    "url" : "http://seclists.org/fulldisclosure/2022/Jul/14"
  }, {
    "type" : "WEB",
    "url" : "http://seclists.org/fulldisclosure/2022/Mar/29"
  }, {
    "type" : "WEB",
    "url" : "http://seclists.org/fulldisclosure/2022/May/35"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2022/01/15/1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2021-12-25T19:15:00Z"
  }
}