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…

Browse: All 2021 CVEs · All vendors

CVSS score: 9.0 Critical
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA KEV: Yes — actively exploited (added 2023-05-01, remediation due 2023-05-22)
Ransomware: Known ransomware campaign use
Weakness (CWE): CWE-917
Published: 2021-12-14
Last modified: 2026-06-17
NVD status: Analyzed

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 products

apache log4j
cvat computer vision annotation tool
intel audio development kit
intel datacenter manager
intel genomics kernel library
intel oneapi
intel secure device onboard
intel sensor solution firmware development kit
intel system debugger
intel system studio
siemens sppa-t3000 ses3000 firmware
siemens captial

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

Required action (CISA)

Apply updates per vendor instructions. Federal remediation deadline: 2023-05-22.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.

References

FAQ

Is CVE-2021-45046 actively exploited?

Yes. CISA added CVE-2021-45046 to its Known Exploited Vulnerabilities (KEV) catalog on 2023-05-01, with a federal remediation deadline of 2023-05-22. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

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

CVE-2021-45046 has a CVSS base score of 9.0 (Critical). Its vector string is CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.