CVE-2011-3414
HighExploitedThe CaseInsensitiveHashProvider.getHashCode function in the HashTable implementation in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 computes hash values for form parameters without restricting the ability to trigger hash collisions…
Published Dec 29, 2011 · Updated Apr 28, 2026
Key Facts
Patch immediately- CVE-2011-3414 is a high-severity vulnerability (CVSS 7.8 v2) affecting Windows 7 (Microsoft), Windows Server 2003 (Microsoft), Windows Server 2008 (Microsoft) and 2 more products.
- It is exploited in the wild, listed in Industry KEV feed since Jan 17, 2012. No public exploit code is known.
- EPSS estimates a 58% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v2
7.8
AV:N/AC:L/Au:N/C:N/I:N/A:C
EPSS (30-day exploit likelihood)
58%
Higher than 99.0% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
None known
Get the full CVE-2011-3414 brief as a PDF
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Description
The CaseInsensitiveHashProvider.getHashCode function in the HashTable implementation in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters, aka "Collisions in HashTable May Cause DoS Vulnerability."
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jan 17, 2012 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
13 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 7Microsoft | See advisory | n/a |
| Windows Server 2003Microsoft | See advisory | n/a |
| Windows Server 2008Microsoft | r2 | n/a |
| Windows VistaMicrosoft | See advisory | n/a |
| Windows XpMicrosoft | sp3-unknown | n/a |
Timeline
Publicly disclosed
Dec 29, 2011
Added to Industry KEV feed
Jan 17, 2012
Last updated
Apr 28, 2026
Weakness Type
- CWE-399
References
- exploitVulnCheck exploitation report
- other20111228 n.runs-SA-2011.004 - web programming languages and platforms - DoS through hash table
- otherMS11-100
- otheroval:org.mitre.oval:def:14588
- otherVU#903934
FAQ
Common Questions.
The CaseInsensitiveHashProvider.getHashCode function in the HashTable implementation in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attack…
Affected: Windows 7 (Microsoft); Windows Server 2003 (Microsoft); Windows Server 2008 (Microsoft) versions r2, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jan 17, 2012.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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