PoC Index

CVE-2021-45046

KEV RANSOMWARECRITICAL 9.0EPSS 100.0%

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.

CVSS v3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H
CVSS v2.0
5.1 MEDIUMAV:N/AC:H/Au:N/C:P/I:P/A:P
EPSS
99.98% chance of exploitation in the next 30 days, 100th percentile
CISA KEV
added 2023-05-01, used in ransomware campaigns
Nuclei
critical · CWE-917
Published
2021-12-14
Updated
2025-10-21

Proof-of-concept exploits (14)

Nuclei templates (1)

References

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