Threats / Microsoft / CVE-2024-21351
CVE-2024-21351
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
Microsoft Windows SmartScreen security feature bypass allows attackers to inject code and achieve code execution, potentially exposing data or disrupting system availability.
Verdict
Today item — known-exploited.
A code injection vulnerability in Windows SmartScreen permits attackers to circumvent security protections and execute arbitrary code. Active exploitation in the wild increases risk to unpatched systems.
CISA KEV Yes · 2024-02-135EPSS 0.30344 (verify live)6CVSS 7.63CISA SSVC Exploitation: active · Automatable: no · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
7 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 2024-02-13).
Probability (EPSS)
EPSS 0.30344 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.6 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L/E:U/RL:O/RC:C) · Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-94 Code Injection — weakness family: Injection.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: partialCISA'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 the same day 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 payload designed to bypass SmartScreen's detection mechanisms.
Business
Security controls fail to prevent malware delivery, increasing breach surface.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I inject code through the bypassed SmartScreen interface to achieve execution on the target system.
Business
Arbitrary code execution enables unauthorized access to sensitive data and system resources.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistence or move laterally within the compromised environment.
Business
System availability is compromised and confidential information is at risk of exfiltration.
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