CVE-2021-3176 in BusinessCTI Enterprise Client
Summary
by MITRE • 01/29/2021
The chat window of the Mitel BusinessCTI Enterprise (MBC-E) Client for Windows before 6.4.15 and 7.x before 7.1.2 could allow an attacker to gain access to user information by sending certain code, due to improper input validation of http links. A successful exploit could allow an attacker to view user information and application data.
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Analysis
by VulDB Data Team • 02/21/2021
The CVE-2021-3176 vulnerability affects the Mitel BusinessCTI Enterprise client software for windows systems, specifically targeting versions prior to 6.4.15 and 7.x prior to 7.1.2. This security flaw resides within the chat window functionality of the application, creating a critical exposure that enables unauthorized access to sensitive user information and application data. The vulnerability stems from inadequate input validation mechanisms when processing http links within the chat interface, allowing malicious actors to exploit this weakness through carefully crafted code injection attempts.
The technical implementation of this vulnerability demonstrates a classic input validation flaw that aligns with CWE-20, which describes improper input validation as a fundamental weakness in software security. The flaw occurs when the application fails to properly sanitize or validate user-supplied http links before processing them within the chat window context. This allows attackers to inject malicious code that can be executed within the application's security boundaries, potentially leading to information disclosure and unauthorized data access. The vulnerability specifically targets the application's handling of web links in chat communications, where user input is not adequately filtered or escaped before being processed.
Operationally, this vulnerability presents a significant risk to organizations utilizing Mitel BusinessCTI Enterprise systems, as it creates an attack vector that can be exploited remotely without requiring elevated privileges. An attacker could send malicious http links through chat functionality, potentially gaining access to user information, session data, or other sensitive application resources. The impact extends beyond simple information disclosure, as the vulnerability could enable further exploitation attempts such as session hijacking or privilege escalation within the application's security context. This makes it particularly dangerous in enterprise environments where the application handles confidential business communications and user data.
Mitigation strategies for CVE-2021-3176 should prioritize immediate patching of affected systems to version 6.4.15 or 7.1.2, respectively, as these releases contain the necessary security fixes. Organizations should also implement network-level controls to monitor and restrict outbound http traffic from the affected application, particularly focusing on chat functionality. Additional defensive measures include implementing strict input validation policies for all user-supplied content, deploying web application firewalls to filter malicious requests, and establishing monitoring procedures to detect unusual chat activity patterns. Security teams should also consider disabling or restricting chat functionality until proper patches are deployed, following the principle of least privilege and minimizing the attack surface. The vulnerability's classification under ATT&CK technique T1059.007 for input validation weaknesses emphasizes the importance of implementing robust sanitization and validation controls to prevent similar exploitation attempts across the enterprise environment.