Cyber Resilience

CVE-2024-21643

HighRCE

Published: 10 January 2024

Published
10 January 2024
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
EPSS Score 0.0063 70.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-21643 is a high-severity Code Injection (CWE-94) vulnerability in Microsoft Identitymodel Extensions. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 29.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

IdentityModel Extensions for .NET provide assemblies for web developers that wish to use federated identity providers for establishing the caller's identity. Anyone leveraging the `SignedHttpRequest`protocol or the `SignedHttpRequestValidator`is vulnerable. Microsoft.IdentityModel trusts the `jku`claim by default for the `SignedHttpRequest`protocol. This raises…

more

the possibility to make any remote or local `HTTP GET` request. The vulnerability has been fixed in Microsoft.IdentityModel.Protocols.SignedHttpRequest. Users should update all their Microsoft.IdentityModel versions to 7.1.2 (for 7x) or higher, 6.34.0 (for 6x) or higher.

CWE(s)
CWE-94

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1046 Network Service Discovery Discovery
Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation.
attack.mitre.org →
T1552.005 Cloud Instance Metadata API Credential Access
Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
attack.mitre.org →
Why these techniques?

SSRF via trusted jku claim in SignedHttpRequest enables exploitation of public-facing .NET applications (T1190), internal network service discovery (T1046), querying cloud metadata (T1522), and accessing unsecured cloud credentials from instance metadata (T1552.005).

Affected Assets

microsoft
identitymodel extensions
≤ 6.34.0 · 7.0.0 — 7.1.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-34 Non-modifiable Executable Programs
addresses: CWE-94

Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.

SC-44 Detonation Chambers
addresses: CWE-94

Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.

SI-10 Information Input Validation
addresses: CWE-94

Validates inputs used in dynamic code generation to block injected directives.

SI-16 Memory Protection
addresses: CWE-94

Directly prevents execution of attacker-supplied code written into data memory regions.

References