Security readout for executives and security teams
Plain-English summary
This flaw can let an attacker bypass Windows SmartScreen protections after a user interacts with malicious content. Successful exploitation may enable unauthorized code execution or system changes. Its 7.6 CVSS score and inclusion in CISA’s Known Exploited Vulnerabilities catalog make prompt patching a business priority.
Executive priority
Treat as a high-priority patching item because exploitation is known and no authentication is required. Track remediation to completion, prioritizing frequently used workstations and closing unsupported-system gaps. The user-interaction requirement reduces immediacy compared with fully automatic compromise, but does not justify delay.
Technical view
CVE-2024-21351 is a Windows SmartScreen security-feature bypass affecting the listed Windows 10, Windows 11, and Windows Server releases. CVSS 3.1 rates it 7.6: network-accessible, low complexity, no privileges required, but user interaction is required. Expected impacts are high integrity impact and limited confidentiality and availability impact.
Likely exposure
Exposure is likely where listed Windows versions remain without Microsoft’s corresponding security update. User-operated endpoints are especially relevant because exploitation requires user interaction. The supplied evidence does not establish whether SmartScreen configuration changes exposure or identify specific vulnerable update levels.
Exploitation context
CISA lists CVE-2024-21351 in its Known Exploited Vulnerabilities catalog, supporting active exploitation. The supplied sources do not describe campaign prevalence, attacker groups, delivery methods, or exploitation mechanics, so those details should not be inferred.
Researcher notes
The strongest evidence is the Microsoft advisory, CVSS vector, affected-product list, and CISA KEV status. The bundle does not provide root-cause details, proof-of-concept information, campaign telemetry, update identifiers, or configuration-dependent exposure. Validate those details directly against Microsoft’s advisory before making detection or exception decisions.
Mitigation direction
- Apply Microsoft’s security update for CVE-2024-21351 across every affected and supported Windows release.
- Prioritize user-operated endpoints and any affected servers where interactive use occurs.
- Check current Microsoft guidance for release-specific update identifiers and any additional mitigations.
Validation and detection
- Inventory devices running each Windows edition and build listed in the advisory.
- Verify installation of Microsoft’s applicable CVE-2024-21351 security update through endpoint-management reporting.
- Investigate update failures, excluded devices, and unsupported Windows installations.
- Review security telemetry for SmartScreen-bypass alerts or related suspicious activity, without assuming absence of alerts proves safety.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2024-21351 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.6 (3.1)
- Known Exploited
- Yes
- Published
Vector: 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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L/E:U/RL:O/RC:C2.84.7microsoftVulnerability scoring details
Base CVSS 3.1 score
7.6HighVector: 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
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2024-21351 added to CISA KEV
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2024-02-13T00:00:00.000Z: CVE-2024-21351 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- Windows SmartScreen Security Feature Bypass VulnerabilityCVE reference, microsoft · vendor-advisory, patch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21351CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.