Vulnerability

CVE-2021-45046

Critical· 9.0KEVEXPLOITCVSS9EPSS94%

.rules3/5

Apache Log4j2 Deserialization of Untrusted Data Vulnerability

Apache Log4j2 contains a deserialization of untrusted data vulnerability due to the incomplete fix of CVE-2021-44228, where the Thread Context Lookup Pattern is vulnerable to remote code execution in certain non-default configurations.

Threat signal

100/100

Severe

Severity

critical

CVSS

9.0

EPSS

94%

Active

KEV

CISA KEV — actively exploited

Ransomware: Known1118d overdue

AffectedApache — Log4j2

Added to KEV

2023-05-01

Federal patch due (BOD 22-01)

2023-05-22

Required action (CISA verbatim)

Apply updates per vendor instructions.

Vendor advisory + references

CISA description: “Apache Log4j2 contains a deserialization of untrusted data vulnerability due to the incomplete fix of CVE-2021-44228, where the Thread Context Lookup Pattern is vulnerable to remote code execution in certain non-default configurations.”

CVSS

v3.1Open in FIRST calculator →

9.0/ 10CRITICALCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityHighRequires conditions outside attacker's control (race, brute-force, configuration
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionNoneFully automated — no victim action needed.
ScopeChangedImpact extends beyond the vulnerable component (e.g. sandbox escape).
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

94.3%

probability of exploitation in next 30 days

p100

higher than 100% of all CVEs

3-day trend↑ 0pp

Statistically about to be weaponized — top-tier triage urgency.

Vendor VEX

No VEX statements published for CVE-2021-45046. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: yes
impact: total
mission: support

Lifecycle

2021-12-16Vendor advisory · amazon-linuxALAS2-2021-1730 — ALAS2-2021-1730 (critical): aws-kinesis-agent
2021-12-18Vendor advisory · amazon-linuxALAS2-2021-1731 — ALAS2-2021-1731 (critical): java-17-amazon-corretto, java-11-amazon-corretto, ja
2021-12-18Vendor advisory · amazon-linuxAL2-ALAS2CORRETTO8-2021-001-(critical):-java-1.8.0-ama — ALAS2CORRETTO8-2021-001 (critical): java-1.8.0-amazon-corretto
2021-12-18Vendor advisory · amazon-linuxAL2-ALAS2JAVA-OPENJDK11-2021-001-(critical):-java-11-o — ALAS2JAVA-OPENJDK11-2021-001 (critical): java-11-openjdk
2023-05-01Added to CISA KEVransomware: Known
2023-05-01Public exploit observedmetasploit
2023-05-01Published
2023-05-22Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

Entity graph

5 nodes · 4 edges · click to pivot

CVEActorVendor advisoryIOCNews

Vendor advisories

Mentions in news & research

research:snykLog4j 2.15 vulnerability CVE-2021-45046 upgraded to a critical severity arbitrary code execution2021-12-17

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.