CVE-2015-2532 in Lync Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Microsoft Lync Server 2013 allows remote attackers to inject arbitrary web script or HTML via a crafted URL, aka "Lync Server XSS Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 06/14/2022
The CVE-2015-2532 vulnerability represents a critical cross-site scripting flaw in Microsoft Lync Server 2013 that enables remote attackers to execute malicious web scripts or HTML code through specially crafted URLs. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically targeting the web interface components of the Lync Server platform. The vulnerability stems from inadequate input validation and output encoding mechanisms within the server's web-based management interfaces and communication protocols. Attackers can exploit this weakness by constructing malicious URLs that contain script code which gets executed when victims navigate to these crafted links or when the server processes user-supplied input in web requests.
The technical implementation of this vulnerability occurs within the Lync Server 2013 web application layer where user-provided data is not properly sanitized before being rendered in web responses. When a user clicks on a maliciously crafted URL or when the server processes certain web requests containing unescaped characters, the injected script code executes in the context of the victim's browser session. This allows attackers to perform actions such as stealing session cookies, redirecting users to malicious sites, defacing web pages, or executing arbitrary commands within the victim's browser environment. The vulnerability is particularly concerning because it affects the core communication infrastructure that organizations rely on for internal and external communications, making it a prime target for sophisticated attack campaigns.
From an operational impact perspective, this vulnerability poses significant risks to enterprise environments that depend on Lync Server 2013 for voice, video, and instant messaging services. Organizations may experience unauthorized access to sensitive communication data, potential data exfiltration through session hijacking, and disruption of critical business communication channels. The vulnerability can be exploited to gain unauthorized access to user sessions, potentially allowing attackers to eavesdrop on conversations, access contact lists, and compromise the confidentiality and integrity of corporate communications. Additionally, the information disclosure aspect of this vulnerability means that attackers could potentially extract sensitive data about users, server configurations, or communication patterns, which could be used for further targeting or exploitation. The attack surface is particularly wide given that Lync Server 2013 is commonly deployed in enterprise environments where users frequently interact with web-based management interfaces and communication features.
The mitigation strategies for CVE-2015-2532 should include immediate deployment of Microsoft security patches and updates that address the input validation and output encoding deficiencies in the Lync Server 2013 platform. Organizations should implement web application firewalls and content filtering mechanisms to detect and block malicious URLs containing script code. Network segmentation and access controls should be strengthened to limit exposure of the Lync Server components to untrusted networks. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in related systems and applications. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for spearphishing attachments, making it a potential entry point for broader attack chains. Organizations should also implement comprehensive monitoring solutions to detect unusual network traffic patterns and user behavior that may indicate exploitation attempts, while maintaining up-to-date threat intelligence feeds to stay informed about related attack patterns and emerging threats targeting similar communication platforms.