Summary
generated automatically from NVD dataApache Log4j2 versions from 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) fail to guard against uncontrolled recursion caused by self-referential lookups. An attacker who controls Thread Context Map data can supply a crafted string that triggers the recursion and causes a denial of service. The issue is fixed in Log4j 2.17.0, 2.12.3, and 2.3.1, and is rated 5.9 (MEDIUM) under CVSS v3.1.
NVD description
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
EPSS · FIRST.org
100.0%probability of exploitation in the next 30 days
Higher than 99% of scored CVEs
EPSS (Exploit Prediction Scoring System) estimates, from observed exploitation activity, how likely a CVE is to be exploited in the next 30 days. It complements CVSS, which measures severity, not likelihood. Score of 2026-10-19, recomputed daily by FIRST.org.
CVSS v3.1 Score
Information
- Published
- 18 déc. 2021
- Updated
- 25 août 2026
- Status
- Modified
- Source
- security@apache.org
Affected products
Weaknesses (CWE)
References (26)
- http://www.openwall.com/lists/oss-security/2021/12/19/1Mailing ListMitigationThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-501673.pdfThird Party Advisory
- https://logging.apache.org/log4j/2.x/security.htmlRelease NotesVendor Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211218-0001/Third Party Advisory
- https://www.debian.org/security/2021/dsa-5024Third Party Advisory
- https://www.kb.cert.org/vuls/id/930724Third Party AdvisoryUS Government Resource
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatchThird Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatchThird Party Advisory
- https://www.oracle.com/security-alerts/cpujul2022.htmlThird Party Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-1541/Third Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2021/12/19/1Mailing ListMitigationThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdfThird Party Advisory
- + 11 more references on NVD
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