CRITICAL CISA KEV

CVE-2021-45046

CVSS v3

9

CRITICAL

EPSS Score

94.3%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

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.

CISA Known Exploited Vulnerability

Date Added
5/1/2023
Patch Due Date
5/22/2023
Ransomware Use
Known

Technical details

Published
12/14/2021

Frequently asked questions

What is CVE-2021-45046?

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.

Is CVE-2021-45046 actively exploited?

Yes. CVE-2021-45046 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 5/22/2023.

What is the CVSS score for CVE-2021-45046?

CVE-2021-45046 has a CVSS v3 base score of 9 (CRITICAL severity).

Is CVE-2021-45046 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.