CVE-2014-0253.net Framework Vulnerability
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…
Published Feb 12, 2014 · Updated Apr 28, 2026
Key Facts
Patch immediately- CVE-2014-0253 is a medium-severity vulnerability (CVSS 5.0 v2) affecting .net Framework (Microsoft).
- It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Feb 11, 2014. No public exploit code is known.
- EPSS estimates a 39% 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.
Scores
CVSS v2
5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P
EPSS (30-day exploit likelihood)
39%
Higher than 98.5% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
42/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Feb 11, 2014
-1 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
2
Reports of active use
Description
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."
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CIRCL KEV | Feb 11, 2014 | n/a | Not reported |
| Industry KEV feed | Feb 11, 2014 | n/a | Not reported |
Affected Products
7 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| .net FrameworkMicrosoft | 1.1-sp1, 2.0-sp2, 3.5, 3.5.1, 4.0, 4.5, 4.5.1 | n/a |
Timeline
Added to CIRCL KEV
Feb 11, 2014
Added to Industry KEV feed
Feb 11, 2014
Publicly disclosed
Feb 12, 2014
Last updated
Apr 28, 2026
Weakness Type
- CWE-20 Improper Input Validation
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- other103162
- otherMS14-009
- other56793
FAQ
Common Questions.
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, a…
Affected: .net Framework (Microsoft) versions 1.1-sp1, 2.0-sp2, 3.5, 3.5.1, 4.0, 4.5, 4.5.1. The full list is in the CVE brief.
It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Feb 11, 2014.
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.
Is CVE-2014-0253 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
Request A Demo