CVE-2021-45046

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2023-05-01. Federal remediation due 2023-05-22.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

99.98% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 100.0% of scored records. A rank, not a probability.

NVD base score

9.0 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-12-14 16:55Z4 YR AGO

Last updated

2025-10-21 23:25Z10 MO AGO

Reserved

2021-12-14

Assigning CNA

apache

Record state

PUBLISHED

Severity

Critical (CVSS 9.0)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses

• CWE-917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')Base

Data version

5.1

Document digest

d09334e06328ff54bb7f9931f5836895851ce68cfc3dccb6f6a5dc21cf88a2b7

• psirt.global.sonicwall.comhttps://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032x_refsource_CONFIRM
• www.oracle.comhttps://www.oracle.com/security-alerts/alert-cve-2021-44228.htmlx_refsource_CONFIRM
• www.cve.orghttps://www.cve.org/CVERecord?id=CVE-2021-44228x_refsource_MISC
• www.openwall.com[oss-security] 20211214 CVE-2021-45046: Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attackhttp://www.openwall.com/lists/oss-security/2021/12/14/4mailing-listx_refsource_MLIST
• logging.apache.orghttps://logging.apache.org/log4j/2.x/security.htmlx_refsource_CONFIRM
• www.kb.cert.orgVU#930724https://www.kb.cert.org/vuls/id/930724third-party-advisoryx_refsource_CERT-VN
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdfx_refsource_CONFIRM
• www.intel.comhttps://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.htmlx_refsource_CONFIRM
• tools.cisco.com20211210 Vulnerabilities in Apache Log4j Library Affecting Cisco Products: December 2021https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbdvendor-advisoryx_refsource_CISCO
• www.openwall.com[oss-security] 20211215 Re: CVE-2021-45046: Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attackhttp://www.openwall.com/lists/oss-security/2021/12/15/3mailing-listx_refsource_MLIST
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdfx_refsource_CONFIRM
• www.debian.orgDSA-5022https://www.debian.org/security/2021/dsa-5022vendor-advisoryx_refsource_DEBIAN
• www.openwall.com[oss-security] 20211218 Re: CVE-2021-45046: Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attackhttp://www.openwall.com/lists/oss-security/2021/12/18/1mailing-listx_refsource_MLIST
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdfx_refsource_CONFIRM
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfx_refsource_CONFIRM
• lists.fedoraproject.orgFEDORA-2021-5c9d12a93ehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2021-abbe24e41chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ/vendor-advisoryx_refsource_FEDORA
• www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.htmlx_refsource_MISC
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.htmlx_refsource_MISC
• www.oracle.comhttps://www.oracle.com/security-alerts/cpujul2022.htmlx_refsource_MISC
• security.gentoo.orghttps://security.gentoo.org/glsa/202310-16
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-45046government-resource