Threats / Microsoft / CVE-2019-0543
CVE-2019-0543
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
Windows improperly handles authentication requests, allowing privilege escalation. An attacker who exploits this vulnerability could run processes with elevated privileges.
Verdict
Today item, not a backlog item.
This authentication handling flaw enables local privilege escalation on Windows systems. Active exploitation in the wild and ransomware campaign activity indicate significant real-world risk despite moderate EPSS score.
CISA KEV Yes · 2022-03-154Ransomware use Flagged4EPSS 0.04718 (verify live)5CVSS 7.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-15), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.04718 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) · Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-287 Improper Authentication — weakness family: Authentication.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1162 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious authentication request to bypass Windows privilege validation mechanisms.
Business
Attacker gains elevated process execution capability on affected Windows endpoints.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary code with system-level privileges to install malware or establish persistence.
Business
Ransomware operators deploy encryption payloads across compromised infrastructure with full system access.
3
Lateral reach — past segmentation narrative 3
Attacker
I move laterally through the network using elevated credentials and system access.
Business
Ransomware campaigns spread to critical systems, maximizing encryption scope and extortion leverage.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05