Log4Shell — Apache Log4j Improper input validation

CVE-2021-45105

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…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.740 (98.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-45105?
CVE-2021-45105 is a medium-severity vulnerability in Apache Log4j, classified under Improper Input Validation. CVSS score: 5.9/10. Published 2021-12-18.
How severe is CVE-2021-45105?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2021-45105 known to be exploited?
148 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.