Threats / Microsoft / CVE-2020-1027
CVE-2020-1027
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
Windows Kernel elevation of privilege vulnerability allowing arbitrary code execution with elevated permissions through improper memory object handling.
Verdict
Today item — known-exploited.
A kernel-level privilege escalation flaw in Windows that enables attackers to execute code with system-level permissions. Active exploitation in the wild demonstrates practical threat; CWE-787 buffer overflow indicates memory corruption as the attack vector.
CISA KEV Yes · 2022-05-234EPSS 0.04447 (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 2022-05-23).
Probability (EPSS)
EPSS 0.04447 — 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-787 Out-of-bounds Write — weakness family: Memory safety.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 768 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 input that triggers improper memory object handling in the Windows Kernel.
Business
Attacker gains execution context within kernel space, bypassing user-mode security boundaries.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary code with elevated system privileges on the compromised host.
Business
Complete system compromise enables installation of persistent malware, credential theft, and lateral movement across the network.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistence and expand access to connected systems and sensitive data.
Business
Organizational infrastructure, intellectual property, and customer data face direct exposure to exfiltration and destruction.
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