CVE-2021-1544 in Webex Meetings Client
Summary
by MITRE • 06/04/2021
A vulnerability in logging mechanisms of Cisco Webex Meetings client software could allow an authenticated, local attacker to gain access to sensitive information. This vulnerability is due to unsafe logging of application actions. An attacker could exploit this vulnerability by logging onto the local system and accessing files containing the logged details. A successful exploit could allow the attacker to gain access to sensitive information, including meeting data and recorded meeting transcriptions.
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Analysis
by VulDB Data Team • 06/07/2021
The vulnerability identified as CVE-2021-1544 represents a critical security flaw within the Cisco Webex Meetings client software that stems from improper logging practices and inadequate data sanitization mechanisms. This weakness specifically targets the application's logging infrastructure, creating an avenue for authenticated local attackers to extract sensitive information from the system. The vulnerability manifests when the software performs unsafe logging of application actions, storing potentially sensitive data in log files that remain accessible to local users with authentication credentials. The flaw resides in the fundamental design approach to logging within the client software, where system activities and user interactions are recorded without proper consideration for data sensitivity and access controls.
The technical exploitation of this vulnerability requires an attacker to first authenticate to the local system, which provides them with the necessary access level to examine the application's log files. Once authenticated, the attacker can navigate to the locations where the Webex Meetings client stores its log data and extract information that may contain meeting details, participant information, and recorded meeting transcriptions. This unsafe logging behavior creates a persistent data exposure risk, as the log files remain accessible even after the application has closed or the user has logged out. The vulnerability essentially transforms the application's legitimate logging functionality into a data exfiltration vector, where the very mechanism designed to track application behavior becomes a security liability.
The operational impact of CVE-2021-1544 extends beyond simple information disclosure, as it compromises the confidentiality of sensitive business communications and personal data. Organizations utilizing Cisco Webex Meetings for video conferencing, collaborative meetings, and remote work environments face significant risks when this vulnerability exists in their systems. The exposure of meeting data and transcriptions could lead to competitive intelligence theft, privacy violations, and potential regulatory compliance issues. The vulnerability particularly affects enterprises that handle confidential information, legal proceedings, medical consultations, or any scenario where meeting content must remain protected from unauthorized access. The local privilege requirement reduces the attack surface complexity, but the persistent nature of log files means that the information remains accessible until explicitly deleted or the system is rebooted.
Security professionals should consider this vulnerability in the context of the CWE-532 principle which addresses the insertion of sensitive information into log files, and it aligns with ATT&CK technique T1005 for data from local system. The vulnerability demonstrates a classic case of inadequate input validation and output sanitization in logging mechanisms, where the software fails to properly handle sensitive data during the logging process. Organizations should implement immediate mitigations including restricting local file system access to log directories, implementing proper log file permissions, and establishing regular log cleanup procedures. The recommended approach involves configuring the application to either sanitize sensitive data before logging or to store logs in secure locations with appropriate access controls. Additionally, security teams should monitor for unauthorized access to application log files and implement automated alerting for suspicious file access patterns. The vulnerability underscores the importance of secure coding practices and proper security testing of logging mechanisms, particularly in applications that handle sensitive user data and business communications.