CVE-2024-21395 in Dynamics 365
Summary
by MITRE • 02/13/2024
Microsoft Dynamics 365 (on-premises) Cross-site Scripting Vulnerability
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/04/2024
This vulnerability exists in Microsoft Dynamics 365 on-premises deployments and represents a cross-site scripting flaw that allows attackers to inject malicious scripts into web applications. The vulnerability stems from insufficient input validation and output encoding mechanisms within the application's web interface components. Attackers can exploit this weakness by crafting specially formatted input data that gets rendered back to users without proper sanitization, enabling execution of arbitrary JavaScript code in the victim's browser context.
The technical implementation of this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting conditions where untrusted data is improperly incorporated into web pages without adequate validation or encoding. The flaw typically manifests when user-supplied data is directly embedded into HTML output without proper HTML escaping or context-appropriate encoding. This allows malicious actors to inject script tags, event handlers, or other malicious payloads that execute in the browser of authenticated users.
Operational impact of this vulnerability extends beyond simple script execution as it can lead to session hijacking, credential theft, data exfiltration, and privilege escalation within the Dynamics 365 environment. An attacker who successfully exploits this vulnerability can potentially access sensitive business data, manipulate customer records, modify sales processes, or gain administrative privileges depending on the user's role within the system. The attack surface is particularly concerning in on-premises deployments where organizations may have less frequent security updates compared to cloud-based solutions.
Mitigation strategies should include implementing comprehensive input validation controls at multiple layers of the application architecture including client-side and server-side validation, enforcing strict output encoding for all dynamic content, and deploying web application firewalls to detect and block malicious payloads. Organizations should also implement proper security headers such as Content Security Policy to limit script execution sources, conduct regular security testing including automated scanning and manual penetration testing, and ensure timely patch management for Microsoft Dynamics 365 components. The ATT&CK framework categorizes this vulnerability under T1059.007 for scripting and T1566.001 for spearphishing with social engineering techniques that could be leveraged to deliver the malicious payloads.
Additional protective measures include implementing role-based access controls to limit the impact of successful exploitation, monitoring application logs for suspicious activities, and conducting regular security awareness training for administrators and end-users. Organizations should also establish secure coding practices and perform threat modeling exercises to identify potential injection points within their Dynamics 365 implementations. The vulnerability represents a critical risk that requires immediate attention through both technical controls and organizational security measures to prevent unauthorized access to business-critical data and systems.