.NET Framework Denial of Service Vulnerability
CVE-2021-24111
Security Vulnerability
Released: Feb 9, 2021
Last updated: Feb 16, 2021
- Assigning CNA
- Microsoft
- CVE.org link
- CVE-2021-24111
- Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
- Metrics
- CVSS:3.1 7.5 / 6.5Base score metrics: 7.5 / Temporal score metrics: 6.5
Metric
Value
Base score metrics(8)
Attack Vector
This metric reflects the context by which vulnerability exploitation is possible. The Base Score increases the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable component.
Network
The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity
This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Such conditions may require the collection of more information about the target or computational exceptions. The assessment of this metric excludes any requirements for user interaction in order to exploit the vulnerability. If a specific configuration is required for an attack to succeed, the Base metrics should be scored assuming the vulnerable component is in that configuration.
Low
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required
This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.
None
The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction
This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise the vulnerable component. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
None
The vulnerable system can be exploited without any interaction from any user.
Scope
Does a successful attack impact a component other than the vulnerable component? If so, the Base Score increases and the Confidentiality, Integrity and Authentication metrics should be scored relative to the impacted component.
Unchanged
An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality
This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
None
There is no loss of confidentiality within the impacted component.
Integrity
This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.
None
There is no loss of integrity within the impacted component.
Availability
This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. It refers to the loss of availability of the impacted component itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of an impacted component.
High
There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Temporal score metrics(3)
Exploit Code Maturity
This metric measures the likelihood of the vulnerability being attacked, and is typically based on the current state of exploit techniques, public availability of exploit code, or active, 'in-the-wild' exploitation.
Unproven
No publicly available exploit code is available, or an exploit is theoretical.
Remediation Level
The Remediation Level of a vulnerability is an important factor for prioritization. The typical vulnerability is unpatched when initially published. Workarounds or hotfixes may offer interim remediation until an official patch or upgrade is issued. Each of these respective stages adjusts the temporal score downwards, reflecting the decreasing urgency as remediation becomes final.
Official Fix
A complete vendor solution is available. Either the vendor has issued an official patch, or an upgrade is available.
Report Confidence
This metric measures the degree of confidence in the existence of the vulnerability and the credibility of the known technical details. Sometimes only the existence of vulnerabilities are publicized, but without specific details. For example, an impact may be recognized as undesirable, but the root cause may not be known. The vulnerability may later be corroborated by research which suggests where the vulnerability may lie, though the research may not be certain. Finally, a vulnerability may be confirmed through acknowledgement by the author or vendor of the affected technology. The urgency of a vulnerability is higher when a vulnerability is known to exist with certainty. This metric also suggests the level of technical knowledge available to would-be attackers.
Confirmed
Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.
Please see Common Vulnerability Scoring System for more information on the definition of these metrics.
Exploitability
The following table provides an exploitability assessment for this vulnerability at the time of original publication.
- Publicly disclosed
- No
- Exploited
- No
- Exploitability assessment
- Exploitation Less Likely
FAQ
I am running Windows Server 2008, Windows 7, or Windows Server 2008 R2 and I cannot install the Security Only updates for any of the 4.X versions of Microsoft .NET Framework. How do I protect my system from this vulnerability?
There is a known issue with the Monthly Rollup and Security Only updates for the 4.X versions of .NET Framework installed on Windows Server 2008, Windows 7, and Windows Server 2008 R2.
If you are unable to install a Monthly Rollup Security Only update, a version 2 is available that addresses the known issue. See the How to obtain and install the update section of the Article for the update you are attempting to install.
If you are unable to install a Security Only update Monthly Rollup, for a workaround to this known issue see the Known issues in this update section of the Article for the update you are attempting to install.
Acknowledgements
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.
Security Updates
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.
Release date Descending
Product
Platform
Impact
Max Severity
Article
Download
Build Number
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2012 R2 (Server Core installation)
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1909 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1909 for ARM64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server, version 1909 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1909 for x64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2019
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2019 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.7.2
Windows 10 Version 1803 for ARM64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.7.2
Windows 10 Version 1803 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2
Windows Server 2016
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2
Windows 10 Version 1607 for x64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.7.2
Windows Server 2019
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.7.2
Windows Server 2019 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.7.2
Windows 10 Version 1803 for x64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2
Windows Server 2016 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2
Windows 10 Version 1607 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 2004 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 2004 for ARM64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 20H2 for ARM64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server, version 20H2 (Server Core Installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 2004 for x64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server, version 2004 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 20H2 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.6
Windows Server 2008 for x64-based Systems Service Pack 2
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.6
Windows Server 2008 for 32-bit Systems Service Pack 2
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2012 (Server Core installation)
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2012 R2
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows RT 8.1
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2016
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2012
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 8.1 for x64-based systems
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2008 R2 for x64-based Systems Service Pack 1
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 7 for x64-based Systems Service Pack 1
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1607 for x64-based Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 8.1 for 32-bit systems
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 7 for 32-bit Systems Service Pack 1
Denial of Service
Important
- -
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1607 for 32-bit Systems
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows Server 2016 (Server Core installation)
Denial of Service
Important
- -
Feb 9, 2021
Microsoft .NET Framework 4.8
Windows 10 Version 1809 for x64-based Systems
Denial of Service
Important
- -
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Disclaimer
The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
Revisions
version
revisionDate
description
1.1
Feb 16, 2021
Corrected Download and Article links for affected versions of Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 installed on Windows Server 2012 in the Security Updates table. This is an informational change only.
1.0
Feb 9, 2021
Information published.
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