CVE-2021-44832: Log4j core Improper Input Validation And Injection Vulnerability

MODERATE
Advisory Identifier: GHSA-8489-44mv-ggj8
CVSS 6.6
CWE-20 CWE-74
Published
Advisory Summary

CVE-2021-44832 is a MODERATE (CVSS 6.6) improper input validation and injection vulnerability (CWE-20: Improper Input Validation) affecting Log4j core libraries in the Maven ecosystem. The issue involves improper input validation and injection in apache log4j2. Remediation is available by upgrading affected packages to version 2.3.2, 2.12.4, 2.17.1, 1.9.2, 1.10.9, 1.11.13, 2.0.14.

CVE-2021-44832 at a Glance

CVE Identifier CVE-2021-44832
GHSA Identifier GHSA-8489-44mv-ggj8
Severity MODERATE
CVSS v3.1 Base Score 6.6
CWE Classification CWE-20: Improper Input Validation
Affected Product Log4j core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.6

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

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required High (PR:H)
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-2021-44832

To remediate this vulnerability, upgrade all affected Log4j core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.apache.logging.log4j:log4j-core fixed: 2.3.2
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.3.2</version>
</dependency>
org.apache.logging.log4j:log4j-core fixed: 2.12.4
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.12.4</version>
</dependency>
org.apache.logging.log4j:log4j-core fixed: 2.17.1
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.17.1</version>
</dependency>
org.ops4j.pax.logging:pax-logging-log4j2 fixed: 1.9.2
<dependency>
    <groupId>org.ops4j.pax.logging</groupId>
    <artifactId>pax-logging-log4j2</artifactId>
    <version>1.9.2</version>
</dependency>
org.ops4j.pax.logging:pax-logging-log4j2 fixed: 1.10.9
<dependency>
    <groupId>org.ops4j.pax.logging</groupId>
    <artifactId>pax-logging-log4j2</artifactId>
    <version>1.10.9</version>
</dependency>
org.ops4j.pax.logging:pax-logging-log4j2 fixed: 1.11.13
<dependency>
    <groupId>org.ops4j.pax.logging</groupId>
    <artifactId>pax-logging-log4j2</artifactId>
    <version>1.11.13</version>
</dependency>
org.ops4j.pax.logging:pax-logging-log4j2 fixed: 2.0.14
<dependency>
    <groupId>org.ops4j.pax.logging</groupId>
    <artifactId>pax-logging-log4j2</artifactId>
    <version>2.0.14</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=org.apache.logging.log4j

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-44832, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.logging.log4j

Analyze the terminal output to locate any version of Log4j core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.3.2), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.logging.log4j 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-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Log4j core, 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

Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix releases 2.3.2 and 2.12.4) are vulnerable to an attack where an attacker with permission to modify the logging configuration file can construct a malicious configuration using a JDBC Appender with a data source referencing a JNDI URI which can execute remote code. This issue is fixed by limiting JNDI data source names to the java protocol in Log4j2 versions 2.17.1, 2.12.4, and 2.3.2. # Affected packages Only the `org.apache.logging.log4j:log4j-core` package is directly affected by this vulnerability. The `org.apache.logging.log4j:log4j-api` should be kept at the same version as the `org.apache.logging.log4j:log4j-core` package to ensure compatability if in use. This issue does not impact default configurations of Log4j2 and requires an attacker to have control over the Log4j2 configuration, which reduces the likelihood of being exploited.

CVE-2021-44832 Affected Log4j core Versions

7 component(s)
Fixed Versions:
2.3.22.12.42.17.11.9.21.10.91.11.132.0.14
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.logging.log4j:log4j-core
Maven
≥ 2.0-beta7
< 2.3.2
2.3.2
org.apache.logging.log4j:log4j-core
Maven
≥ 2.4
< 2.12.4
2.12.4
org.apache.logging.log4j:log4j-core
Maven
≥ 2.13.0
< 2.17.1
2.17.1
org.ops4j.pax.logging:pax-logging-log4j2
Maven
≥ 1.8.0
< 1.9.2
1.9.2
org.ops4j.pax.logging:pax-logging-log4j2
Maven
≥ 1.10.0
< 1.10.9
1.10.9
org.ops4j.pax.logging:pax-logging-log4j2
Maven
≥ 1.11.0
< 1.11.13
1.11.13
org.ops4j.pax.logging:pax-logging-log4j2
Maven
≥ 2.0.0
< 2.0.14
2.0.14

References

NVD — CVE-2021-44832 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-44832
cert-portal.siemens.com/productcert/pdf/ssa... WEB
https://cert-portal.siemens.com/productcert/pdf/ssa-784507.pdf
Log4j core Source Repository REPOSITORY
https://github.com/apache/logging-log4j2
issues.apache.org/jira/browse/log4j2-... WEB
https://issues.apache.org/jira/browse/LOG4J2-3293
lists.apache.org/thread/s1o5vlo78ypq... WEB
https://lists.apache.org/thread/s1o5vlo78ypqxnzn6p8zf6t9shtq5143
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2021/12/msg00036.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EVV25FXL4FU5X6X5BSL7RLQ7T6F65MRA
Log4j core Security Information SECURITY
https://security.netapp.com/advisory/ntap-20220104-0001
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T57MPJUW3MA6QGWZRTMCHHMMPQNVKGFC
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EVV25FXL4FU5X6X5BSL7RLQ7T6F65MRA
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T57MPJUW3MA6QGWZRTMCHHMMPQNVKGFC
Log4j core Security Information SECURITY
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
Log4j core Security Information SECURITY
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
Log4j core Security Information SECURITY
https://www.oracle.com/security-alerts/cpuapr2022.html
Log4j core Security Information SECURITY
https://www.oracle.com/security-alerts/cpujan2022.html
Log4j core Security Information SECURITY
https://www.oracle.com/security-alerts/cpujul2022.html
Log4j core Security Information SECURITY
http://www.openwall.com/lists/oss-security/2021/12/28/1

Frequently Asked Questions

What is CVE-2021-44832?
CVE-2021-44832 is a security vulnerability in Log4j core involving Improper Input Validation and Injection in Apache Log4j2 under CWE-20: Improper Input Validation.
Which Log4j core versions are affected?
Affected versions include releases prior to 2.3.2, 2.12.4, 2.17.1, 1.9.2, 1.10.9, 1.11.13, 2.0.14 across affected packages: org.apache.logging.log4j:log4j-core, org.ops4j.pax.logging:pax-logging-log4j2.
What version fixes CVE-2021-44832?
Upgrading to 2.3.2, 2.12.4, 2.17.1, 1.9.2, 1.10.9, 1.11.13, 2.0.14 (or the latest patched release for your respective branch) resolves the vulnerability.
Is log4j-core affected?
Yes, org.apache.logging.log4j:log4j-core is affected in releases prior to 2.3.2, 2.12.4, 2.17.1. Upgrade your dependency to 2.3.2, 2.12.4, 2.17.1 or later.
Is pax-logging-log4j2 affected?
Yes, org.ops4j.pax.logging:pax-logging-log4j2 is affected in releases prior to 1.9.2, 1.10.9, 1.11.13, 2.0.14. Upgrade your dependency to 1.9.2, 1.10.9, 1.11.13, 2.0.14 or later.
What is the CVSS score of CVE-2021-44832?
CVE-2021-44832 has a CVSS v3.1 base score of 6.6 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-44832?
CVE-2021-44832 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check Maven dependencies for CVE-2021-44832?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.logging.log4j'. 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-8489-44mv-ggj8",
  "modified" : "2026-06-09T10:31:58Z",
  "published" : "2022-01-04T16:14:20Z",
  "aliases" : [ "CVE-2021-44832" ],
  "summary" : "Improper Input Validation and Injection in Apache Log4j2",
  "details" : "Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix releases 2.3.2 and 2.12.4) are vulnerable to an attack where an attacker with permission to modify the logging configuration file can construct a malicious configuration using a JDBC Appender with a data source referencing a JNDI URI which can execute remote code. This issue is fixed by limiting JNDI data source names to the java protocol in Log4j2 versions 2.17.1, 2.12.4, and 2.3.2.\n\n\n# Affected packages\nOnly the `org.apache.logging.log4j:log4j-core` package is directly affected by this vulnerability. The `org.apache.logging.log4j:log4j-api` should be kept at the same version as the `org.apache.logging.log4j:log4j-core` package to ensure compatability if in use.\n\nThis issue does not impact default configurations of Log4j2 and requires an attacker to have control over the Log4j2 configuration, which reduces the likelihood of being exploited.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0-beta7"
      }, {
        "fixed" : "2.3.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.4"
      }, {
        "fixed" : "2.12.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
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    } ]
  }, {
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    },
    "ranges" : [ {
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      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.10.0"
      }, {
        "fixed" : "1.10.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.11.0"
      }, {
        "fixed" : "1.11.13"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.0.14"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-44832"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-784507.pdf"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/logging-log4j2"
  }, {
    "type" : "WEB",
    "url" : "https://issues.apache.org/jira/browse/LOG4J2-3293"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread/s1o5vlo78ypqxnzn6p8zf6t9shtq5143"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2021/12/msg00036.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EVV25FXL4FU5X6X5BSL7RLQ7T6F65MRA"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T57MPJUW3MA6QGWZRTMCHHMMPQNVKGFC"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EVV25FXL4FU5X6X5BSL7RLQ7T6F65MRA"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T57MPJUW3MA6QGWZRTMCHHMMPQNVKGFC"
  }, {
    "type" : "WEB",
    "url" : "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20220104-0001"
  }, {
    "type" : "WEB",
    "url" : "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujul2022.html"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2021/12/28/1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-74" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-12-28T21:14:19Z",
    "nvd_published_at" : "2021-12-28T20:15:00Z"
  }
}