CVE-2016-3309

HIGH(7.8)KEVRansomwareElevated Risk

Microsoft Windows Kernel Privilege Escalation Vulnerability

Description

CVE-2016-3309 is a high-severity privilege escalation vulnerability affecting Microsoft Windows. A privilege escalation vulnerability exists when the Windows kernel fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. This vulnerability has been associated with ransomware campaigns, heightening its risk profile. CISA has added CVE-2016-3309 to the Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. With an EPSS score of 45.23% (97.5th percentile), this vulnerability has a significant probability of being exploited.

KEV Information

Vendor
Microsoft
Product
Windows
Date Added
March 15, 2022
Due Date
April 5, 2022
Required Action
Apply updates per vendor instructions.

CVSS Score

Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HOpen in Calculator
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
1.8
Impact Score
5.9

Affected Products

VendorProductVersion
microsoftwindows 10 1507-
microsoftwindows 10 1511-
microsoftwindows 10 1607-
microsoftwindows 7-
microsoftwindows 8.1-
microsoftwindows rt 8.1-
microsoftwindows server 2008-; r2
microsoftwindows server 2012-; r2
microsoftwindows vista-

Multiple CVSS Assessments

Source: [email protected](Primary)
7.8
HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0(Secondary)
7.8
HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Weakness Type

No CWE Assigned

No specific CWE has been assigned to CVE-2016-3309. Based on the vulnerability description, this is a privilege escalation issue in Microsoft Windows where a privilege escalation vulnerability exists when the Windows kernel fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode.

Impact Analysis

CVE-2016-3309 represents a significant threat to organizations using Microsoft Windows, carrying a CVSS score of 7.8. Successful exploitation can fully compromise the confidentiality, integrity, and availability of affected systems. Attackers can access sensitive data, modify system configurations or data, and disrupt service availability. The documented association with ransomware campaigns makes this vulnerability particularly dangerous, as threat actors actively leverage it for initial access or privilege escalation in ransomware operations.

Exploit Maturity

CVE-2016-3309 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming real-world exploitation. The EPSS score of 45.23% (97.5th percentile) indicates a significant probability of exploitation in the wild. This vulnerability has been linked to ransomware campaigns, indicating that well-resourced threat actors are actively incorporating it into their attack chains.

Remediation

  1. Apply vendor patches immediately as required by CISA KEV: Apply updates per vendor instructions. Update Microsoft Windows to the latest available version that addresses this vulnerability.
  2. Until the patch is applied, enforce the principle of least privilege by limiting local user access to only those who require it, and restrict the ability to execute untrusted applications on affected systems.
  3. Given the ransomware association, ensure endpoint detection and response (EDR) solutions are active on all affected systems and monitor for indicators of compromise including unusual process execution, file encryption activity, and lateral movement.
  4. Verify the patch deployment across all instances of Microsoft Windows in your environment using vulnerability scanning to confirm no systems remain exposed.
  5. Review and update your organization's vulnerability management process to ensure CISA KEV entries with a remediation deadline of 2022-04-05 are addressed within the required timeframe.

Technical Details

CVE-2016-3309 is a security vulnerability affecting Microsoft Windows. A privilege escalation vulnerability exists when the Windows kernel fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. The vulnerability is exploitable with local access to the target system, with low attack complexity, requiring low-level privileges. The CVSS 3.1 base score of 7.8 (HIGH) reflects high confidentiality impact, high integrity impact, and high availability impact.

Frequently Asked Questions

Is CVE-2016-3309 being actively exploited?

Yes. CVE-2016-3309 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. The EPSS score of 45.23% (97.5th percentile) indicates a significant probability of exploitation. This vulnerability has also been associated with ransomware campaigns.

What products are affected by CVE-2016-3309?

CVE-2016-3309 primarily affects Microsoft Windows, as well as Microsoft Windows 10 1507, Microsoft Windows 10 1511, Microsoft Windows 10 1607. Organizations should check whether any instances of the affected software are running in their environment.

How do I fix CVE-2016-3309?

Apply updates per vendor instructions. Until the update is applied, limit local access privileges and monitor for suspicious activity on affected systems.

How severe is CVE-2016-3309?

CVE-2016-3309 has a CVSS 3.1 score of 7.8, rated HIGH. This high severity rating indicates significant potential impact on affected systems. The association with ransomware campaigns further elevates the operational risk posed by this vulnerability.

CVSS Score

7.8
HIGH(7.8)

EPSS Score

EPSS Score20.63%
EPSS Percentile97.3%

Dates

PublishedAugust 9, 2016
Last ModifiedJune 17, 2026
StatusAnalyzed
CVSS Versionv3.1

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