Cyber Resilience

CVE-2017-0263

HighCISA KEVActive ExploitationEUVD ExploitedPublic PoC

Published: 12 May 2017

Published
12 May 2017
Modified
22 April 2026
KEV Added
10 February 2022
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.2077 95.7th percentile
Risk Priority 48 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2017-0263 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 4.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).

Deeper analysis

The vulnerability is a use-after-free flaw, tracked as CWE-416, in the Win32k kernel-mode drivers of Microsoft Windows. It affects Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold through 1703, and Windows Server 2016. The issue carries a CVSS 3.1 base score of 7.8 and is described as an elevation-of-privilege condition reachable from a local context.

Local users who can execute code on an affected system may exploit the flaw by running a specially crafted application. Successful exploitation grants the attacker elevated privileges, with the potential to achieve full control over confidentiality, integrity, and availability of the target system.

Microsoft published an advisory for CVE-2017-0263 that directs administrators to the corresponding security update. Public exploit code for the issue is available, confirming that working proof-of-concept attacks have been developed and shared.

EU & UK References

Vulnerability details

The kernel-mode drivers in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allow local users to…

more

gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability."

CWE(s)
KEV Date Added
10 February 2022

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10 1507
all versions
microsoft
windows 10 1511
all versions
microsoft
windows 10 1607
all versions
microsoft
windows 10 1703
all versions
microsoft
windows 7
all versions
microsoft
windows 8.1
all versions
microsoft
windows rt 8.1
all versions
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
all versions

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires applying the vendor security update that eliminates the Win32k use-after-free flaw before local exploitation can succeed.

prevent

Implements memory-protection safeguards that can block or contain use-after-free exploitation attempts in kernel-mode drivers.

prevent

Enforces least-privilege restrictions on local accounts so that successful exploitation yields only limited additional rights rather than full system control.

References