Incomplete fix for Apache Log4j vulnerability
# Impact The 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. ## 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. # Mitigation Log4j 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). Log4j 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.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2021-45046US | critical9.0OT critical | KEV | ||
It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers with control over Threa… | ||||
references
External citations — patches, advisories, analysis.
- https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdfWEB
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfWEB
- https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdfWEB
- https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdfWEB
- https://github.com/apache/logging-log4j2/compare/rel/2.3...rel/2.3.1WEB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCYWEB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJWEB
- https://logging.apache.org/log4j/2.x/security.htmlWEB
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