HIGH
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 Dec 30, 2011
8.5
HIGHCVSS 2.0
EPSS 43.69%
Description
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."
Affected products
No data.
OR
- n/a
- n/a
- n/a
- n/a
- n/a
- n/a
- n/a
- n/a
- r2
- n/a
- n/a
- n/a
- sp3
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
8.5 HIGH NVD
AV:N/AC:M/Au:S/C:C/I:C/A:C
Access Vector Network
Access Complexity Medium
Authentication Single
Confidentiality Impact Complete
Integrity Impact Complete
Availability Impact Complete
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
43.69% 0.43691
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.43691
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (42 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 43.69% (0.43691) | 98.70th | v5 (v2026.06.15) |
| Aug 14, 2026 | 43.69% (0.43691) | 98.63th | v5 (v2026.06.15) |
| Jun 15, 2026 | 45.58% (0.45576) | 98.63th | v5 (v2026.06.15) |
| Mar 4, 2026 | 52.83% (0.52829) | 97.89th | v4 (v2025.03.14) |
| Mar 1, 2026 | 25.58% (0.25583) | 96.15th | v4 (v2025.03.14) |
| Feb 4, 2026 | 52.83% (0.52829) | 97.87th | v4 (v2025.03.14) |
| Feb 1, 2026 | 25.58% (0.25583) | 96.11th | v4 (v2025.03.14) |
| Jan 4, 2026 | 52.83% (0.52829) | 97.84th | v4 (v2025.03.14) |
| Jan 1, 2026 | 25.58% (0.25583) | 96.09th | v4 (v2025.03.14) |
| Dec 23, 2025 | 52.83% (0.52829) | 97.83th | v4 (v2025.03.14) |
| Dec 4, 2025 | 78.02% (0.78018) | 98.95th | v4 (v2025.03.14) |
| Dec 1, 2025 | 50.79% (0.50788) | 97.74th | v4 (v2025.03.14) |
| Nov 4, 2025 | 78.02% (0.78018) | 98.96th | v4 (v2025.03.14) |
| Nov 1, 2025 | 50.79% (0.50788) | 97.73th | v4 (v2025.03.14) |
| Oct 18, 2025 | 78.02% (0.78018) | 98.96th | v4 (v2025.03.14) |
| Oct 4, 2025 | 83.53% (0.83531) | 99.24th | v4 (v2025.03.14) |
| Oct 1, 2025 | 62.06% (0.62064) | 98.30th | v4 (v2025.03.14) |
| Sep 4, 2025 | 83.53% (0.83531) | 99.24th | v4 (v2025.03.14) |
| Sep 1, 2025 | 62.06% (0.62064) | 98.30th | v4 (v2025.03.14) |
| Aug 30, 2025 | 83.53% (0.83531) | 99.24th | v4 (v2025.03.14) |
| Aug 4, 2025 | 86.63% (0.86632) | 99.38th | v4 (v2025.03.14) |
| Aug 1, 2025 | 70.15% (0.70150) | 98.62th | v4 (v2025.03.14) |
| Jul 4, 2025 | 86.63% (0.86632) | 99.37th | v4 (v2025.03.14) |
| Jul 1, 2025 | 70.15% (0.70150) | 98.59th | v4 (v2025.03.14) |
| Jun 4, 2025 | 86.63% (0.86632) | 99.37th | v4 (v2025.03.14) |
| Jun 1, 2025 | 70.15% (0.70150) | 98.58th | v4 (v2025.03.14) |
| May 4, 2025 | 86.63% (0.86632) | 99.36th | v4 (v2025.03.14) |
| May 1, 2025 | 70.15% (0.70150) | 98.58th | v4 (v2025.03.14) |
| Mar 30, 2025 | 86.63% (0.86632) | 99.38th | v4 (v2025.03.14) |
| Mar 29, 2025 | 82.28% (0.82279) | 99.01th | v4 (v2025.03.14) |
| Mar 17, 2025 | 86.63% (0.86632) | 99.38th | v4 (v2025.03.14) |
| Mar 1, 2025 | 92.81% (0.92806) | 99.28th | v3 (v2023.03.01) |
| Jan 15, 2025 | 94.06% (0.94056) | 99.38th | v3 (v2023.03.01) |
| Dec 12, 2024 | 95.75% (0.95753) | 99.51th | v3 (v2023.03.01) |
| Aug 19, 2024 | 95.21% (0.95207) | 99.38th | v3 (v2023.03.01) |
| Jun 29, 2024 | 96.21% (0.96212) | 99.53th | v3 (v2023.03.01) |
| Mar 13, 2024 | 96.42% (0.96418) | 99.54th | v3 (v2023.03.01) |
| Nov 24, 2023 | 96.65% (0.96647) | 99.54th | v3 (v2023.03.01) |
| Jul 29, 2023 | 96.83% (0.96831) | 99.52th | v3 (v2023.03.01) |
| Mar 7, 2023 | 96.75% (0.96755) | 99.39th | v3 (v2023.03.01) |
| Mar 6, 2023 | 53.78% (0.53783) | 98.79th | v2 (v2022.01.01) |
| Feb 4, 2022 | 53.78% (0.53783) | 98.43th | v2 (v2022.01.01) |
Weaknesses (1)
References (3)
- http://www.us-cert.gov/cas/techalerts/TA11-347A.html third-party-advisoryx_refsource_CERTUS Government Resource
- https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-100 vendor-advisoryx_refsource_MS
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14363 vdb-entrysignaturex_refsource_OVAL
| Link | Providers | Tags |
|---|---|---|
| http://www.us-cert.gov/cas/techalerts/TA11-347A.html | third-party-advisoryx_refsource_CERTUS Government Resource | |
| https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-100 | vendor-advisoryx_refsource_MS | |
| https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14363 | vdb-entrysignaturex_refsource_OVAL |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner microsoft
Published Dec 30, 2011
Updated Aug 6, 2024
Reserved Sep 9, 2011
Link CVE-2011-3416
CISA Vulnrichment
Updated n/a