CVE-2011-0661

The SMB Server service in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 does not properly validate fields in SMB requests, which allows remote attackers to execute arbitrary code via a malformed request in a (1) SMBv1 or (2) SMBv2 packet, aka "SMB Transaction Parsing Vulnerability."

Published: 2011-04-13 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2011-0661 is rated High Risk (77.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 65.17%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +3.27% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2011-0661

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 61.91% 65.17% +3.27%
2 2025-12-27 65.17% 61.91% -3.27%
3 2025-10-28 — 65.17% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-0661

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2011-0661

Affected software / configurations for CVE-2011-0661

Vendor Product Version Raw CPE
microsoft windows_2003_server — cpe:2.3:o:microsoft:windows_2003_server:*:sp2:*:*:*:*:*:*
microsoft windows_7 — cpe:2.3:o:microsoft:windows_7:-:*:*:*:*:*:*:*
microsoft windows_7 — cpe:2.3:o:microsoft:windows_7:-:sp1:x64:*:*:*:*:*
microsoft windows_7 — cpe:2.3:o:microsoft:windows_7:-:sp1:x86:*:*:*:*:*
microsoft windows_server_2003 — cpe:2.3:o:microsoft:windows_server_2003:*:sp2:*:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:*:itanium:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:*:x32:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:*:x64:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x32:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x64:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:itanium:*:*:*:*:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:*:itanium:*:*:*:*:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:*:x64:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:sp1:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:*:sp3:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:-:sp2:x64:*:*:*:*:*

References for CVE-2011-0661

cvelogic Threat Intelligence