CVE-2023-21572 in Dynamics 365
Summary
by MITRE • 02/14/2023
Microsoft Dynamics 365 (on-premises) Cross-site Scripting Vulnerability
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Analysis
by VulDB Data Team • 03/15/2023
Microsoft Dynamics 365 on-premises installations contain a cross-site scripting vulnerability that allows remote attackers to inject malicious scripts into web applications through improperly validated user input. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically representing a weakness in input validation where user-supplied data is not adequately sanitized before being rendered in web responses. The flaw exists in the web interface components of the on-premises deployment model, creating an attack surface where malicious actors can manipulate the application's behavior by injecting script code into fields that should only accept legitimate data.
The technical implementation of this vulnerability stems from insufficient validation of input parameters within the Dynamics 365 web forms and data entry interfaces. When users submit data through web forms or interact with dynamic content, the application fails to properly sanitize or encode user-supplied values before displaying them in subsequent web responses. This allows attackers to craft malicious payloads that execute within the context of other users' browsers, potentially leading to session hijacking, data theft, or unauthorized administrative actions. The vulnerability is particularly concerning in enterprise environments where Dynamics 365 serves as a critical business application handling sensitive customer and operational data.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a foothold for more sophisticated attacks within the organization's network infrastructure. According to ATT&CK framework, this vulnerability maps to T1566 (Phishing) and T1059 (Command and Scripting Interpreter) techniques, as attackers can leverage the XSS flaw to deliver malicious payloads through social engineering campaigns or establish persistent access through beaconing scripts. Organizations using on-premises Dynamics 365 deployments face risks of unauthorized data access, privilege escalation, and potential lateral movement within their network. The attack vector typically involves crafting malicious input through web forms, URL parameters, or API endpoints that are not properly validated, allowing the injected scripts to execute when other users view the affected content.
Mitigation strategies for CVE-2023-21572 should focus on implementing comprehensive input validation and output encoding mechanisms across all user-facing interfaces. Organizations must ensure that all user-supplied data undergoes strict sanitization before being processed or displayed, utilizing proper encoding techniques such as HTML entity encoding for output rendering. Security patches from Microsoft should be applied immediately to address the root cause of the vulnerability, while network segmentation and web application firewalls can provide additional layers of protection. The implementation of Content Security Policy headers and proper input validation libraries can significantly reduce the attack surface. Organizations should also conduct regular security assessments and penetration testing to identify similar vulnerabilities in their Dynamics 365 deployments, as well as implement monitoring solutions to detect potential exploitation attempts. Compliance with industry standards such as NIST SP 800-53 and ISO 27001 requires organizations to maintain robust input validation controls to prevent XSS attacks and protect against unauthorized access to sensitive business applications.