win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008…

published 2011-10-12 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-1979

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 2.3%; EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits: 1; Exploit-DB

win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 does not properly validate user-mode input, which allows local users to gain privileges or cause a denial of service (NULL pointer dereference and system crash) via a crafted application, aka "Win32k Null Pointer De-reference Vulnerability."

Timeline

2011-10-12 Published
2011-10-23 First public exploit (EDB-18024)

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 21 mo ago (2025-01-21)

Exploit prediction

2.27% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

EDB-18024 Microsoft Win32k - Null Pointer De-reference (PoC) (MS11-077) dos, 2011-10-23

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
CNA	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD	2.0	7.2	AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness

CWE-476 NULL Pointer Dereference

References

docs.microsoft.com /en-us/security-updates/securitybulletins/2011/ms11-077
vendor-advisory
securitytracker.com /id?1026165
vdb-entry
oval.cisecurity.org /repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12935
vdb-entry, signature

Sources

CVE List CVE-2011-1985
NVD CVE-2011-1985

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary