CVE-2021-45046: Log4j core Incomplete Fix For Apache Log4j Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7rjr-3q55-vv33",
  "modified" : "2026-10-02T20:21:52Z",
  "published" : "2021-12-14T18:01:28Z",
  "aliases" : [ "CVE-2021-45046" ],
  "summary" : "Incomplete fix for Apache Log4j vulnerability",
  "details" : "# Impact\n\nThe fix to address [CVE-2021-44228](https://nvd.nist.gov/vuln/detail/CVE-2021-44228) in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allow attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in a remote code execution (RCE) attack. \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\n# Mitigation\n\nLog4j 2.16.0 fixes this issue by removing support for message lookup patterns and disabling JNDI functionality by default. This issue can be mitigated in prior releases (< 2.16.0) by removing the JndiLookup class from the classpath (example: zip -q -d log4j-core-*.jar org/apache/logging/log4j/core/lookup/JndiLookup.class).\n\nLog4j 2.15.0 restricts JNDI LDAP lookups to localhost by default. Note that previous mitigations involving configuration such as to set the system property `log4j2.formatMsgNoLookups` to `true` do NOT mitigate this specific vulnerability.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.13.0"
      }, {
        "fixed" : "2.16.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.4.0"
      }, {
        "fixed" : "2.12.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.8.0"
      }, {
        "fixed" : "1.9.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.10.0"
      }, {
        "fixed" : "1.10.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.11.0"
      }, {
        "fixed" : "1.11.11"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.ops4j.pax.logging:pax-logging-log4j2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.0.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.3.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-45046"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujul2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/alert-cve-2021-44228.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.openwall.com/lists/oss-security/2021/12/18/1"
  }, {
    "type" : "WEB",
    "url" : "https://www.openwall.com/lists/oss-security/2021/12/15/3"
  }, {
    "type" : "WEB",
    "url" : "https://www.openwall.com/lists/oss-security/2021/12/14/4"
  }, {
    "type" : "WEB",
    "url" : "https://www.kb.cert.org/vuls/id/930724"
  }, {
    "type" : "WEB",
    "url" : "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2021/dsa-5022"
  }, {
    "type" : "WEB",
    "url" : "https://www.cve.org/CVERecord?id=CVE-2021-44228"
  }, {
    "type" : "WEB",
    "url" : "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-45046"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202310-16"
  }, {
    "type" : "WEB",
    "url" : "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd"
  }, {
    "type" : "WEB",
    "url" : "https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032"
  }, {
    "type" : "WEB",
    "url" : "https://logging.apache.org/security.html#CVE-2021-45046"
  }, {
    "type" : "WEB",
    "url" : "https://logging.apache.org/log4j/2.x/security.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/logging-log4j2/compare/rel/2.3...rel/2.3.1"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502", "CWE-917" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-12-14T17:55:00Z",
    "nvd_published_at" : "2021-12-14T19:15:00Z"
  }
}