CVE-2011-3416

The Forms Authentication feature in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 allows remote authenticated users to obtain access to arbitrary user accounts via a crafted username, aka "ASP.Net Forms Authentication Bypass Vulnerability."

Published: 2011-12-30 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2011-3416 is rated High Risk (73.3/100): CVSS High severity, with high exploitation likelihood (EPSS 52.83%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +27.25% 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-2011-3416

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 2026-03-04 25.58% 52.83% +27.25%
2 2026-03-01 52.83% 25.58% -27.25%
3 2026-02-04 — 52.83% —

Full EPSS history (38 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-3416

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.5 2.0 HIGH
AV:N/AC:M/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 6.8 10.0 [email protected]

Weakness enumeration for CVE-2011-3416

Affected software / configurations for CVE-2011-3416

Vendor Product Version Raw CPE
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:*:r2:x64:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:sp2:itanium:*:*:*:*:*
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:x86:*:*:*:*:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:*:itanium:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:-:sp2:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:*:sp2:professional_x64:*:*:*:*:*
microsoft windows_xp sp3 cpe:2.3:o:microsoft:windows_xp:sp3:unknown:english:*:*:*:*:*

References for CVE-2011-3416

cvelogic Threat Intelligence