CVE-2006-6696

CVE-2006-6696 is a medium-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 6.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

• Severity: Medium (CVSS 2.0 base score 6.9)
• EPSS exploit prediction: 3% (87th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-119
• Affected product: Microsoft Windows 2000
• Published: 2006-12-22
• Last modified: 2026-06-16

Description

Double free vulnerability in Microsoft Windows 2000, XP, 2003, and Vista allows local users to gain privileges by calling the MessageBox function with a MB_SERVICE_NOTIFICATION message with crafted data, which sends a HardError message to Client/Server Runtime Server Subsystem (CSRSS) process, which is not properly handled when invoking the UserHardError and GetHardErrorText functions in WINSRV.DLL.

Frequently asked questions

What is CVE-2006-6696?

Double free vulnerability in Microsoft Windows 2000, XP, 2003, and Vista allows local users to gain privileges by calling the MessageBox function with a MB_SERVICE_NOTIFICATION message with crafted data, which sends a HardError message to Client/Server Runtime Server Subsystem (CSRSS) process, which is not properly handled when invoking the UserHardError and GetHardErrorText functions in WINSRV.DLL.

How severe is CVE-2006-6696?

CVE-2006-6696 has a CVSS 2.0 base score of 6.9, rated medium severity.

Is CVE-2006-6696 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-6696?

CVE-2006-6696 primarily affects Microsoft Windows 2000. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2006-6696?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2006-6696 published?

CVE-2006-6696 was published on 2006-12-22 and last updated on 2026-06-16.

References

• http://blogs.technet.com/msrc/archive/2006/12/22/new-report-of-a-windows-vulnerability.aspx
• http://groups.google.ca/group/microsoft.public.win32.programmer.kernel/browse_thread/thread/c5946bf40f227058/7bd7b5d66a4e5aff
• http://isc.sans.org/diary.php?n&storyid=1965
• http://lists.grok.org.uk/pipermail/full-disclosure/2006-December/051394.html
• http://research.eeye.com/html/alerts/zeroday/20061215.html
• http://secunia.com/advisories/23448
• http://securitytracker.com/id?1017433
• http://www.determina.com/security.research/vulnerabilities/csrss-harderror.html
• http://www.kuban.ru/forum_new/forum2/files/19124.html
• http://www.security.nnov.ru/Gnews944.html
• http://www.security.nnov.ru/files/messagebox.c
• http://www.securityfocus.com/archive/1/455061/100/0/threaded
• http://www.securityfocus.com/archive/1/455088/100/0/threaded
• http://www.securityfocus.com/archive/1/455104/100/0/threaded
• http://www.securityfocus.com/archive/1/455158/100/0/threaded
• http://www.securityfocus.com/archive/1/455546/100/0/threaded
• http://www.securityfocus.com/archive/1/466331/100/200/threaded
• http://www.securityfocus.com/bid/21688
• http://www.securityfocus.com/bid/23324
• http://www.vupen.com/english/advisories/2006/5120
• http://www.vupen.com/english/advisories/2007/1325
• https://docs.microsoft.com/en-us/security-updates/securitybulletins/2007/ms07-021
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1816

Affected products (29)

• cpe:2.3:o:microsoft:windows_2000:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2000:*:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2000:*:sp2:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2000:*:sp3:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:datacenter_edition:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:datacenter_edition:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:datacenter_edition:sp1_beta_1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:enterprise_edition:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:enterprise_edition:sp1_beta_1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:sp1:*:enterprise:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:standard:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:standard:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:standard:sp1_beta_1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:web:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:web:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_2003_server:web:sp1_beta_1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:*:december_ctp:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:beta:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:beta1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:beta2:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:*:home:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:*:media_center:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:gold:professional:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp1:home:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp1:media_center:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp2:home:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp2:media_center:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp2:tablet_pc:*:*:*:*:*

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