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.net FrameworkApplication · Microsoft

CVE-2014-0253

MEDIUM · 5.0 CVSS v2.0 Published 2014-02-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5, 3.5.1, 4, 4.5, and 4.5.1 does not properly determine TCP connection states, which allows remote attackers to cause a denial of service (ASP.NET daemon hang) via crafted HTTP requests that trigger persistent resource consumption for a (1) stale or (2) closed connection, as exploited in the wild in February 2014, aka "POST Request DoS Vulnerability."

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Microsoft .NET Framework versions 1.1 SP1 through 4.5.1 improperly determines TCP connection states, allowing remote attackers to send crafted HTTP requests that trigger persistent resource consumption for stale or closed connections, causing the ASP.NET daemon to hang.

MitigationApply Microsoft security updates for .NET Framework. Where patching is not immediately feasible, configure IIS connection timeouts and implement web application firewall rules to detect and mitigate malformed HTTP requests.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
.net FrameworkApplication
Affected:= 1.1= 2.0= 3.5= 3.5.1= 4.0= 4.5= 4.5.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed .NET Framework version
    Open Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full (for .NET 4.x) or HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5 (for earlier versions). Check the Release or Version value. Alternatively, run 'wmic product where "name like 'Microsoft .NET Framework%'" get name,version' in Command Prompt.
    Affected if The installed version falls within 1.1 SP1 through 4.5.1 inclusive.
  2. Verify ASP.NET is enabled
    Check if ASP.NET is installed and enabled. For IIS, run 'aspnet_regiis -lv' from the appropriate .NET Framework folder (e.g., C:\Windows\Microsoft.NET\Framework\v4.0.30319). Or check IIS Manager under ISAPI and CGI Restrictions.
    Affected if ASP.NET is installed and registered with IIS, making the application vulnerable to crafted HTTP requests.
  3. Confirm network-exposed HTTP handler
    Check if IIS is running and accepting HTTP requests. Run 'iisreset' or check IIS Manager for active sites. Verify the server is bound to a public or untrusted network interface.
    Affected if The server accepts HTTP connections from network sources, enabling remote attackers to send malicious requests.
  4. Review IIS connection timeout configuration
    Open IIS Manager, select the site, click Limits under Actions, or check the <httpRuntime> timeout in web.config files. Default connection timeouts may be set to 120 seconds or higher.
    Affected if Connection timeouts are set to default values (not reduced), allowing stale connections to persist and consume resources.

The environment is affected if .NET Framework version 1.1 SP1 through 4.5.1 is installed, ASP.NET is enabled, and the server accepts remote HTTP connections without shortened connection timeouts.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security updates for .NET Framework. Where patching is not immediately feasible, configure IIS connection timeouts and implement web application firewall rules to detect and mitigate malformed HTTP requests.

Fix this in .net Framework Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2014-0253 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data