CVE-2021-45046
Apache Log4j2 Deserialization of Untrusted Data Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 22 May 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 9.0 CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 99.98% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 1 May 2023 · due 22 May 2023 · used in ransomware campaigns
- Weakness
- CWE-917
- Affected
- 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 · siemens/comos · siemens/desigo cc advanced reports · siemens/desigo cc info center · siemens/e-car operation center · siemens/energy engage · siemens/energyip · siemens/energyip prepay · siemens/gma-manager · +35 more
- Source
- security@apache.org
EPSS 100.0% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://logging.apache.org/log4j/2.x/security.html; https://nvd.nist.gov/vuln/detail/CVE-2021-45046
References
- http://www.openwall.com/lists/oss-security/2021/12/14/4Mailing List, Mitigation, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/12/15/3Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/12/18/1Mailing List, Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdfThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY/Mailing List, Release Notes
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ/Mailing List, Release Notes
- https://logging.apache.org/log4j/2.x/security.htmlMitigation, Release Notes, Vendor Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032Third Party Advisory
- https://security.gentoo.org/glsa/202310-16Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbdThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2021-44228Not Applicable
- https://www.debian.org/security/2021/dsa-5022Third Party Advisory
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.htmlThird Party Advisory
- https://www.kb.cert.org/vuls/id/930724Third Party Advisory, US Government Resource
- https://www.oracle.com/security-alerts/alert-cve-2021-44228.htmlThird Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlThird Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2022.htmlThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/12/14/4Mailing List, Mitigation, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/12/15/3Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/12/18/1Mailing List, Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdfThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY/Mailing List, Release Notes
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ/Mailing List, Release Notes
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.