Microsoft Identity Denial of service vulnerability
CVE-2024-21319
Security Vulnerability
Released: Jan 9, 2024
- Assigning CNA
- Microsoft
- CVE.org link
- CVE-2024-21319
- Impact
- Denial of Service
- Max Severity
- Important
- Weakness
- CVSS Source
- Microsoft
- Vector String
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C
- Metrics
- CVSS:3.1 6.8 / 5.9Base score metrics: 6.8 / Temporal score metrics: 5.9
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.
High
The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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.
Changed
An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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
According to the CVSS metric, privileges required is high (PR:H). What does that mean for this vulnerability?
The attacker must have access to the public encrypt key registered with the IDP(Entra ID) for successful exploitation.
How could an attacker exploit this vulnerability?
An attacker could exploit this vulnerability by crafting a malicious JSON Web Encryption (JWE) token with a high compression ratio. This token, when processed by a server, leads to excessive memory allocation and processing time during decompression, causing a denial-of-service (DoS) condition.
It's important to note that the attacker must have access to the public key registered with the IDP(AAD) for successful exploitation.
According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?
A scope change (S:C) in the CVSS metric indicates that successful exploitation of this vulnerability could extend beyond the immediate processing of malicious tokens, affecting the overall availability of the system by causing a denial-of-service (DoS) condition.
Acknowledgements
- Morgan Brown with Microsoft
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
Jan 9, 2024
Microsoft Identity Model v5.0.0 for Nuget
-
Denial of Service
Important
- 5.7.0
Jan 9, 2024
Microsoft Identity Model v7.0.0
-
Denial of Service
Important
- 7.1.2
Jan 9, 2024
Microsoft Identity Model v5.0.0
-
Denial of Service
Important
- 5.7.0
Jan 9, 2024
Microsoft Identity Model v6.0.0
-
Denial of Service
Important
- 6.34.0
Jan 9, 2024
Microsoft Identity Model v7.0.0 for Nuget
-
Denial of Service
Important
- 7.1.2
Jan 9, 2024
Microsoft Identity Model v6.0.0 for Nuget
-
Denial of Service
Important
- 6.34.0
Jan 9, 2024
Microsoft Visual Studio 2022 version 17.8
-
Denial of Service
Important
- 17.8.4
Jan 9, 2024
Microsoft Visual Studio 2022 version 17.4
-
Denial of Service
Important
- 17.4.15
Jan 9, 2024
Microsoft Visual Studio 2022 version 17.6
-
Denial of Service
Important
- 17.6.11
Jan 9, 2024
Microsoft Visual Studio 2022 version 17.2
-
Denial of Service
Important
- 17.2.23
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Revisions
version
revisionDate
description
1.0
Jan 9, 2024
Information published.
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