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Critical 9.0Known exploited (CISA KEV)Published Dec 14, 2021
CVE-2021-45046Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack
Updated under an hour ago ()
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It affects Apache Software Foundation Apache Log4j and 55 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since May 1, 2023; federal agencies had to remediate by May 22, 2023, and it is known to be used in ransomware. Treat that date as your deadline.
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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
- 9.0 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-917
- Known exploited
- Added to CISA KEV May 1, 2023; federal remediation due May 22, 2023; known ransomware useApply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 99.98% (percentile 100)
- Assigned by
- apache
- NVD analysis
- Analyzed
- Record last updated
- Oct 21, 2025
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Apache Software Foundation Apache Log4j apache_software_foundation:apache_log4j (from the name) | from Apache Log4j2 before 2.16.0 | CNA record |
apache log4j apache:log4j | from 2.0.1 before 2.12.2; from 2.13.0 before 2.16.0; 2.0; 2.0; 2.0; 2.0 | NVD |
cvat computer_vision_annotation_tool cvat:computer_vision_annotation_tool | all versions | NVD |
intel audio_development_kit intel:audio_development_kit | all versions | NVD |
intel datacenter_manager intel:datacenter_manager | all versions | NVD |
intel genomics_kernel_library intel:genomics_kernel_library | all versions | NVD |
intel oneapi intel:oneapi | all versions | NVD |
intel secure_device_onboard intel:secure_device_onboard | all versions | NVD |
intel sensor_solution_firmware_development_kit intel:sensor_solution_firmware_development_kit | all versions | NVD |
intel system_debugger intel:system_debugger | all versions | NVD |
intel system_studio intel:system_studio | all versions | NVD |
siemens sppa-t3000_ses3000_firmware siemens:sppa-t3000_ses3000_firmware | all versions | NVD |
siemens captial siemens:captial | before 2019.1; 2019.1; 2019.1 | NVD |
siemens comos siemens:comos | all versions | NVD |
siemens desigo_cc_advanced_reports siemens:desigo_cc_advanced_reports | 4.0; 4.1; 4.2; 5.0; 5.1 | NVD |
siemens desigo_cc_info_center siemens:desigo_cc_info_center | 5.0; 5.1 | NVD |
siemens e-car_operation_center siemens:e-car_operation_center | before 2021-12-13 | NVD |
siemens energy_engage siemens:energy_engage | 3.1 | NVD |
siemens energyip siemens:energyip | 8.5; 8.6; 8.7; 9.0 | NVD |
siemens energyip_prepay siemens:energyip_prepay | 3.7; 3.8 | NVD |
siemens gma-manager siemens:gma-manager | before 8.6.2j-398 | NVD |
siemens head-end_system_universal_device_integration_system siemens:head-end_system_universal_device_integration_system | all versions | NVD |
siemens industrial_edge_management siemens:industrial_edge_management | all versions | NVD |
siemens industrial_edge_management_hub siemens:industrial_edge_management_hub | before 2021-12-13 | NVD |
siemens logo!_soft_comfort siemens:logo!_soft_comfort | all versions | NVD |
siemens mendix siemens:mendix | all versions | NVD |
siemens mindsphere siemens:mindsphere | before 2021-12-11 | NVD |
siemens navigator siemens:navigator | before 2021-12-13 | NVD |
siemens nx siemens:nx | all versions | NVD |
siemens opcenter_intelligence siemens:opcenter_intelligence | through 3.2 | NVD |
siemens operation_scheduler siemens:operation_scheduler | through 1.1.3 | NVD |
siemens sentron_powermanager siemens:sentron_powermanager | 4.1; 4.2 | NVD |
siemens siguard_dsa siemens:siguard_dsa | 4.2; 4.3; 4.4 | NVD |
siemens sipass_integrated siemens:sipass_integrated | 2.80; 2.85 | NVD |
siemens siveillance_command siemens:siveillance_command | through 4.16.2.1 | NVD |
siemens siveillance_control_pro siemens:siveillance_control_pro | all versions | NVD |
siemens siveillance_identity siemens:siveillance_identity | 1.5; 1.6 | NVD |
siemens siveillance_vantage siemens:siveillance_vantage | all versions | NVD |
siemens siveillance_viewpoint siemens:siveillance_viewpoint | all versions | NVD |
siemens solid_edge_cam_pro siemens:solid_edge_cam_pro | all versions | NVD |
siemens solid_edge_harness_design siemens:solid_edge_harness_design | before 2020; 2020; 2020; 2020 | NVD |
siemens spectrum_power_4 siemens:spectrum_power_4 | before 4.70; 4.70; 4.70; 4.70 | NVD |
siemens spectrum_power_7 siemens:spectrum_power_7 | before 2.30; 2.30; 2.30; 2.30 | NVD |
siemens teamcenter siemens:teamcenter | all versions | NVD |
siemens tracealertserverplus siemens:tracealertserverplus | all versions | NVD |
siemens vesys siemens:vesys | before 2019.1; 2019.1; 2019.1; 2019.1 | NVD |
siemens xpedition_enterprise siemens:xpedition_enterprise | all versions | NVD |
siemens xpedition_package_integrator siemens:xpedition_package_integrator | all versions | NVD |
debian debian_linux debian:debian_linux | 10.0; 11.0 | NVD |
sonicwall email_security sonicwall:email_security | before 10.0.12 | NVD |
fedoraproject fedora fedoraproject:fedora | 34; 35 | NVD |
siemens 6bk1602-0aa12-0tp0_firmware siemens:6bk1602-0aa12-0tp0_firmware | before 2.7.0 | NVD |
siemens 6bk1602-0aa22-0tp0_firmware siemens:6bk1602-0aa22-0tp0_firmware | before 2.7.0 | NVD |
siemens 6bk1602-0aa32-0tp0_firmware siemens:6bk1602-0aa32-0tp0_firmware | before 2.7.0 | NVD |
siemens 6bk1602-0aa42-0tp0_firmware siemens:6bk1602-0aa42-0tp0_firmware | before 2.7.0 | NVD |
siemens 6bk1602-0aa52-0tp0_firmware siemens:6bk1602-0aa52-0tp0_firmware | before 2.7.0 | NVD |
References
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032x-refsource-confirm, third-party-advisory
- https://www.oracle.com/security-alerts/alert-cve-2021-44228.htmlx-refsource-confirm, third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-44228x-refsource-misc, not-applicable
- http://www.openwall.com/lists/oss-security/2021/12/14/4mailing-list, x-refsource-mlist, mitigation, third-party-advisory
- https://logging.apache.org/log4j/2.x/security.htmlx-refsource-confirm, mitigation, release-notes, vendor-advisory
- https://www.kb.cert.org/vuls/id/930724third-party-advisory, x-refsource-cert-vn, us-government-resource
- https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdfx-refsource-confirm, third-party-advisory
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.htmlx-refsource-confirm, third-party-advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbdvendor-advisory, x-refsource-cisco, third-party-advisory
- http://www.openwall.com/lists/oss-security/2021/12/15/3mailing-list, x-refsource-mlist, third-party-advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdfx-refsource-confirm, third-party-advisory
- https://www.debian.org/security/2021/dsa-5022vendor-advisory, x-refsource-debian, third-party-advisory
- http://www.openwall.com/lists/oss-security/2021/12/18/1mailing-list, x-refsource-mlist, third-party-advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdfx-refsource-confirm, third-party-advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfx-refsource-confirm, third-party-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY/vendor-advisory, x-refsource-fedora, mailing-list, release-notes
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ/vendor-advisory, x-refsource-fedora, mailing-list, release-notes
- https://www.oracle.com/security-alerts/cpujan2022.htmlx-refsource-misc, patch, third-party-advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlx-refsource-misc, third-party-advisory
- https://www.oracle.com/security-alerts/cpujul2022.htmlx-refsource-misc, third-party-advisory
- https://security.gentoo.org/glsa/202310-16third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-45046us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.