CVE-2011-3416

What it is

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."

At a glance

Exploitability

Can be exploited over the network with a login. High risk of data exposure, data tampering, service disruption.

Exploit odds

43.7% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2011-09-09 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2011-12-30 01:55 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-06-16 23:33 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 43.7% in the next 30 days (EPSS).
• Severity: 8.5 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2011-12-30 01:55 UTC

Last modified

2026-06-16 23:33 UTC

Exploit probability

43.7% · EPSS, next 30 days

Weakness

CWE-264

Record status

Modified

Affected

• Microsoft Windows 7
• Microsoft Windows Server 2003
• Microsoft Windows Server 2008
• Microsoft Windows Server 2008 r2
• Microsoft Windows Vista
• Microsoft Windows Xp
• Microsoft Windows Xp sp3

Attack profile CVSS 2.0 · 8.5

Attack vector

Network

Complexity

Medium

Authentication

Single

Confidentiality

Complete

Integrity

Complete

Availability

Complete

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2011-3416.md and follow it. Check whether this project is affected by CVE-2011-3416. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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