CVE-2015-2359 in Exchange Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the web applications in Microsoft Exchange Server 2013 Cumulative Update 8 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka "Exchange HTML Injection Vulnerability."
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Analysis
by VulDB Data Team • 05/20/2022
The CVE-2015-2359 vulnerability represents a critical cross-site scripting flaw in Microsoft Exchange Server 2013 Cumulative Update 8 that enables remote attackers to execute malicious web scripts or HTML content within the context of affected web applications. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically targeting the web-based interface components of Microsoft Exchange Server. The flaw manifests through unspecified vectors within the Exchange Server web applications, creating an attack surface that can be exploited by malicious actors without requiring authentication or elevated privileges. The vulnerability's impact extends to any user who interacts with the affected Exchange Server web interface, potentially compromising user sessions and data confidentiality.
The technical exploitation of this vulnerability occurs when the web application fails to properly validate or sanitize user-supplied input before rendering it within web pages. Attackers can craft malicious payloads that get executed in the browser context of legitimate users who access the compromised Exchange Server interface. This HTML injection vulnerability allows for various attack vectors including session hijacking, credential theft, redirection to malicious sites, and potentially full compromise of user accounts. The vulnerability's persistence in the Cumulative Update 8 release indicates that Microsoft had not yet addressed this specific flaw in their security updates, leaving organizations exposed to targeted attacks.
Operationally, this vulnerability poses significant risks to enterprise environments relying on Exchange Server 2013 for email services. Organizations may experience unauthorized access to user mailboxes, potential data exfiltration, and compromise of sensitive corporate communications. The attack surface is particularly concerning given that Exchange Server typically serves as a critical communication hub within enterprise networks, making successful exploitation potentially devastating for business continuity and information security. Attackers can leverage this vulnerability to establish persistent access points within the network, using the compromised Exchange Server as a staging ground for further attacks. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet without requiring physical access to the network infrastructure.
Mitigation strategies for CVE-2015-2359 should prioritize immediate deployment of Microsoft's security patches and updates as released in subsequent Cumulative Updates. Organizations should implement comprehensive input validation and output encoding mechanisms within their web applications to prevent similar vulnerabilities from persisting. Network segmentation and access controls should be strengthened to limit exposure of Exchange Server components to untrusted networks. Security monitoring should include detection of suspicious web requests and user behavior anomalies that may indicate exploitation attempts. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities in other web applications. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies. According to ATT&CK framework, this vulnerability maps to T1566 (Phishing) and T1071.001 (Application Layer Protocol: Web Protocols) techniques, as attackers can use the XSS flaw to deliver malicious payloads through email phishing campaigns and web-based attacks. Organizations should also consider implementing web application firewalls and content security policies to provide additional layers of protection against similar injection attacks.