{"id":"CVE-2021-45046","aliases":["GHSA-7rjr-3q55-vv33"],"title":"Incomplete fix for Apache Log4j vulnerability","summary":"Incomplete fix for Apache Log4j vulnerability","severity":"critical","cvss":9,"cwe":["CWE-502","CWE-917"],"vendor":"apache","product":"org.apache.logging.log4j:log4j-core","ecosystem":"maven","affected":["org.apache.logging.log4j:log4j-core >= 2.13.0, < 2.16.0","org.ops4j.pax.logging:pax-logging-log4j2 >= 1.8.0, < 1.9.2","org.ops4j.pax.logging:pax-logging-log4j2 >= 1.10.0, < 1.10.8","org.ops4j.pax.logging:pax-logging-log4j2 >= 1.11.0, < 1.11.11","org.ops4j.pax.logging:pax-logging-log4j2 >= 2.0.0, < 2.0.12","org.apache.logging.log4j:log4j-core >= 2.4.0, < 2.12.2","org.apache.logging.log4j:log4j-core < 2.3.1"],"patched":["org.apache.logging.log4j:log4j-core 2.16.0","org.ops4j.pax.logging:pax-logging-log4j2 1.9.2","org.ops4j.pax.logging:pax-logging-log4j2 1.10.8","org.ops4j.pax.logging:pax-logging-log4j2 1.11.11","org.ops4j.pax.logging:pax-logging-log4j2 2.0.12","org.apache.logging.log4j:log4j-core 2.12.2","org.apache.logging.log4j:log4j-core 2.3.1"],"published":"2021-12-14","updated":"2026-10-02","sourceUpdated":"2026-10-02T20:21:54Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-7rjr-3q55-vv33","references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-45046"},{"url":"https://logging.apache.org/log4j/2.x/security.html"},{"url":"https://www.openwall.com/lists/oss-security/2021/12/14/4"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-44228"},{"url":"https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf"},{"url":"https://www.kb.cert.org/vuls/id/930724"},{"url":"https://www.debian.org/security/2021/dsa-5022"},{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032"},{"url":"https://www.oracle.com/security-alerts/alert-cve-2021-44228.html"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf"},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf"},{"url":"https://www.oracle.com/security-alerts/cpujan2022.html"},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"url":"https://www.oracle.com/security-alerts/cpujul2022.html"},{"url":"https://security.gentoo.org/glsa/202310-16"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY"},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-45046"},{"url":"https://www.openwall.com/lists/oss-security/2021/12/18/1"},{"url":"https://www.openwall.com/lists/oss-security/2021/12/15/3"},{"url":"https://logging.apache.org/security.html#CVE-2021-45046"},{"url":"https://github.com/apache/logging-log4j2/compare/rel/2.3...rel/2.3.1"},{"url":"https://github.com/advisories/GHSA-7rjr-3q55-vv33"}],"tags":["ghsa","maven","kev","in-the-wild","exploit-available"],"epss":0.99977,"epssPercentile":0.9998,"kev":true,"kevDateAdded":"2023-05-01","kevDueDate":"2023-05-22","kevRansomware":true,"exploited":true,"exploits":{"github":11,"githubRepos":["https://github.com/cckuailong/Log4j_CVE-2021-45046","https://github.com/BobTheShoplifter/CVE-2021-45046-Info","https://github.com/tejas-nagchandi/CVE-2021-45046"],"metasploit":["auxiliary/scanner/http/log4shell_scanner"],"nuclei":["CVE-2021-45046"],"checkedAt":"2026-10-02T22:33:43.920Z"},"exploitAvailable":true,"ingestedAt":"2026-10-02T22:33:09.854Z","slug":"CVE-2021-45046","body":"## Overview\n\n# 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.\n\n## Affected packages\n\n- `org.apache.logging.log4j:log4j-core >= 2.13.0, < 2.16.0`\n- `org.ops4j.pax.logging:pax-logging-log4j2 >= 1.8.0, < 1.9.2`\n- `org.ops4j.pax.logging:pax-logging-log4j2 >= 1.10.0, < 1.10.8`\n- `org.ops4j.pax.logging:pax-logging-log4j2 >= 1.11.0, < 1.11.11`\n- `org.ops4j.pax.logging:pax-logging-log4j2 >= 2.0.0, < 2.0.12`\n- `org.apache.logging.log4j:log4j-core >= 2.4.0, < 2.12.2`\n- `org.apache.logging.log4j:log4j-core < 2.3.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `org.apache.logging.log4j:log4j-core 2.16.0`\n- `org.ops4j.pax.logging:pax-logging-log4j2 1.9.2`\n- `org.ops4j.pax.logging:pax-logging-log4j2 1.10.8`\n- `org.ops4j.pax.logging:pax-logging-log4j2 1.11.11`\n- `org.ops4j.pax.logging:pax-logging-log4j2 2.0.12`\n- `org.apache.logging.log4j:log4j-core 2.12.2`\n- `org.apache.logging.log4j:log4j-core 2.3.1`","depth":"hadal","depthScore":99,"depthScoreParts":{"impact":49.5,"likelihood":20,"exploitation":25,"ransomware":5},"changes":[]}