VYPR
Critical severityCISA KEVNVD Advisory· Published Dec 14, 2021· Updated Oct 21, 2025

Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack

CVE-2021-45046

Description

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 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 an information leak and remote code execution in some environments and local code execution in all environments. Log4j 2.16.0 (Java 8) and 2.12.2 (Java 7) fix this issue by removing support for message lookup patterns and disabling JNDI functionality by default.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
org.apache.logging.log4j:log4j-coreMaven
>= 2.13.0, < 2.16.02.16.0
org.apache.logging.log4j:log4j-coreMaven
< 2.12.22.12.2
org.ops4j.pax.logging:pax-logging-log4j2Maven
>= 1.8.0, < 1.9.21.9.2
org.ops4j.pax.logging:pax-logging-log4j2Maven
>= 1.10.0, < 1.10.81.10.8
org.ops4j.pax.logging:pax-logging-log4j2Maven
>= 1.11.0, < 1.11.111.11.11
org.ops4j.pax.logging:pax-logging-log4j2Maven
>= 2.0.0, < 2.0.122.0.12

Affected products

1
  • Apache Software Foundation/Apache Log4jv5
    Range: Apache Log4j2

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

31

News mentions

0

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