Vulnerability detail
Enriched intelligence for a single CVE
Critical
CVE-2021-45046
PUBLISHEDApache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack
- Vendor
- Apache Software Foundation
- Product
- Apache Log4j
- Published
- Dec 14, 2021
- EPSS
- —
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 scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
SSVC decision points
- Exploitation
- active
- Automatable
- No
- Technical impact
- total
References
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032
- https://www.oracle.com/security-alerts/alert-cve-2021-44228.html
- https://www.cve.org/CVERecord?id=CVE-2021-44228
- http://www.openwall.com/lists/oss-security/2021/12/14/4
- https://logging.apache.org/log4j/2.x/security.html
- https://www.kb.cert.org/vuls/id/930724
- https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
- http://www.openwall.com/lists/oss-security/2021/12/15/3
- https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf
- https://www.debian.org/security/2021/dsa-5022
- http://www.openwall.com/lists/oss-security/2021/12/18/1
- https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ/
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://security.gentoo.org/glsa/202310-16
Known exploited vulnerability sources
Catalogues that list this CVE as a known exploited vulnerability.
| Source | Added |
|---|---|
| CISA | May 01, 2023 |
Scanner integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-45046.yaml | Apr 25, 2025 |
Potential proof of concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2021-12-15 09:01:37 UTC · 4 stars
Oh no another one
github · Created 2021-12-15 05:48:53 UTC · 20 stars
Log4j 2.15.0 Privilege Escalation -- CVE-2021-45046
Timeline
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CVE ID Reserved
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CVE Published to Public
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Exploit Used in Malware
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Added to KEVIntel
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Detected by Nuclei