CVE-2014-0257: Microsoft .NET Framework type traversal allows remote code execution

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 19 September 2026. Confidence: high.

high priorityRemote code execution with a 9.3 CVSS score, very high EPSS and public exploit code, though not listed in KEV and requiring some user interaction.

What it is

Microsoft .NET Framework fails to properly determine whether it is safe to execute a method, a flaw Microsoft calls the Type Traversal Vulnerability. A remote attacker can exploit this through a crafted web site or a crafted .NET application that exposes a COM server endpoint, leading to arbitrary code execution in the context of the affected process. Because .NET Framework is widely deployed across supported Windows versions, the exposure is broad.

Impact

An attacker gains arbitrary code execution on the target system, which can lead to full compromise of confidentiality, integrity and availability. In the web-based scenario the code runs within the sandbox of the hosting process, but the flaw is specifically a sandbox escape, so the attacker can break out of that restricted context.

Attack surface

Reached over the network via a crafted web site visited by the victim or via a crafted .NET application that exposes a COM server endpoint; no authentication is required, but the CVSS vector indicates medium access complexity and the web vector implies some user interaction such as browsing to the malicious page.

Exploitation

Not listed in CISA KEV, but EPSS is very high at roughly 0.697 (99.3rd percentile) and public exploit code exists on Exploit-DB, so exploitation is feasible and likely observed in the wild.

What to do

• Apply Microsoft security update MS14-009 for all affected .NET Framework versions (1.0 SP3, 1.1 SP1, 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1).
• Inventory systems still running end-of-life .NET Framework versions and prioritize them for upgrade or isolation.
• Restrict or disable unnecessary COM server endpoints exposed by .NET applications where operationally feasible.
• Enforce browser and email protections that block untrusted content and reduce drive-by exposure to crafted web sites.
• Monitor for and block known exploit traffic and payloads associated with MS14-009.

Detection

• Hunt for processes spawning from .NET runtime hosts (w3wp.exe, iexplore.exe, .NET application hosts) that then launch unusual child processes such as cmd.exe or powershell.exe.
• Monitor for unexpected COM server endpoint registration or activation events tied to .NET assemblies.
• Review web proxy and IDS/IPS logs for requests matching known MS14-009 exploit patterns and Exploit-DB payload signatures.
• Alert on .NET Framework versions below the MS14-009 patch level across endpoints and servers.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.