Threats / Microsoft / CVE-2009-1123
CVE-2009-1123
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
Microsoft Windows kernel fails to properly validate changes to kernel objects, allowing local users to escalate privileges through a crafted application.
Verdict
Today item — known-exploited.
A local privilege escalation vulnerability in the Windows kernel stemming from insufficient validation of kernel object modifications. Exploitation requires local access and a malicious application, but enables attackers to gain system-level control.
CISA KEV Yes · 2022-03-034EPSS 0.04918 (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
2 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 2022-03-03).
Probability (EPSS)
EPSS 0.04918 — 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:N/UI:R/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-20 Improper Input Validation.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 4649 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 an application that modifies unvalidated kernel objects to bypass security checks.
Business
An attacker with local system access can escalate to kernel privileges, compromising system integrity and confidentiality.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute my application on a vulnerable Windows system to trigger the kernel validation flaw.
Business
Compromised systems become fully controlled by the attacker, enabling data theft, malware installation, and lateral movement across the network.
3
Lateral reach — past segmentation narrative 3
Attacker
I maintain kernel-level access to persist threats and evade detection mechanisms.
Business
Organizations face prolonged exposure to advanced threats, regulatory violations, and reputational damage from undetected system compromise.
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