External risk intelligence

.NET Framework and Visual Studio Elevation of Privilege Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2023-36049

The vulnerability affects .NET, .NET Framework, and Visual Studio components, which are primarily developer tools, internal libraries, or backend frameworks. While these can exist in public-facing environments if hosting web applications, they are not inherently internet-facing services by design. Public internet exposure for these products typically requires specific developer or application configuration rather than being a default state.

Microsoft Net Framework

2.03.03.54.6.24.74.7.14.7.24.84.8.13.5.16.0.0 to before 6.0.257.0.0 to before 7.0.148.0.017.2 to before 17.2.2217.4 to before 17.4.1417.6 to before 17.6.1017.7 to be...

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Microsoft's .NET, .NET Framework, and Visual Studio software, potentially allowing unauthorized access and control. This issue, classified as external, presents a significant risk if exploited, as it could compromise the confidentiality, integrity, and availability of affected systems.

Attackers can gain system control.
Confirms potential impact on Microsoft platforms.
Assess exposure and prioritize mitigation.

Attack Path

How an attacker could exploit the issue

Attackers can exploit this vulnerability by sending specially crafted requests to a vulnerable .NET, .NET Framework, or Visual Studio application. This could allow them to elevate their privileges on the affected system.

No special access required.
Triggered by unauthenticated network request.
Leads to privilege escalation.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, this vulnerability could allow an unauthenticated attacker to escalate privileges on a vulnerable system. This could lead to unauthorized access and modification of sensitive system data or user information.

System data and sensitive information at risk.
Attacker could execute code remotely.
System compromise and data exposure.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in .NET, .NET Framework, and Visual Studio affects environments where these components are deployed, potentially including development, testing, and production systems. Owners of applications and services utilizing these Microsoft technologies should first inventory their deployments to identify all instances. Confirming reachability and business criticality will inform prioritization for remediation, coordinating with accountable application or platform owners.

Confirm affected technology presence and criticality.
Identify accountable application or platform owner.
Plan remediation based on confirmed risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the software affected by CVE-2023-36049?

.NET and .NET Framework are software development frameworks used to build and run a wide variety of applications, ranging from backend web services to desktop programs on Windows. Visual Studio is an integrated development environment (IDE) used by developers to write and manage this code. Together, these tools form the foundation for many Microsoft-based enterprise and consumer applications.

How would you explain the vulnerability in CVE-2023-36049?

This vulnerability is classified as Improper Input Validation (CWE-20). In simple terms, the software does not correctly check or sanitize the data it receives from a user or network source. Because of this weakness, an attacker can send specially crafted data to the application, which may trick the system into granting the attacker higher permissions than they should have, resulting in an Elevation of Privilege.

Does this vulnerability require special user actions to trigger?

No. The vulnerability is triggered by sending a specially crafted request over the network to a vulnerable application. An attacker does not need to be authenticated to the system or have pre-existing privileges to initiate the attempt. However, simply having the software installed is not enough; the application must be actively processing network requests for this path to be relevant.

Is my system at risk if it runs .NET or Visual Studio?

Halo Surface Signal notes that while these components are used in many environments, they are not inherently internet-facing services by design. They typically require specific application configurations or web hosting setups to be reachable from the internet. If you are running these tools purely for local development, your exposure is significantly lower than if they are powering a public-facing web application.

What is the first step to address CVE-2023-36049?

You should begin by performing an inventory of your environment to identify all instances of .NET, .NET Framework, and Visual Studio. Once you have a list, determine which applications are critical and evaluate whether they are reachable over the network. Coordinate with your application or platform owners to prioritize updates for the systems that are most exposed or mission-critical.

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36049

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.