CVE-2020-3541 in Webex Meetings Client
Summary
by MITRE
A vulnerability in the media engine component of Cisco Webex Meetings Client for Windows, Cisco Webex Meetings Desktop App for Windows, and Cisco Webex Teams for Windows could allow an authenticated, local attacker to gain access to sensitive information. The vulnerability is due to unsafe logging of authentication requests by the affected software. An attacker could exploit this vulnerability by reading log files that are stored in the application directory. A successful exploit could allow the attacker to gain access to sensitive information, which could be used in further attacks.
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Analysis
by VulDB Data Team • 11/12/2020
This vulnerability resides within the media engine component of Cisco Webex client applications for Windows platforms, specifically affecting Cisco Webex Meetings Client, Cisco Webex Meetings Desktop App, and Cisco Webex Teams for Windows. The flaw represents a critical security oversight in how authentication requests are handled and logged within the application's operational framework. The vulnerability stems from the application's failure to properly secure sensitive authentication data during the logging process, creating an exploitable condition that directly compromises user security. The affected software components store authentication requests in plain text within log files located in the application directory, providing an unintended attack vector for malicious actors.
The technical implementation of this vulnerability aligns with CWE-532, which addresses information exposure through logging mechanisms. The unsafe logging behavior occurs when the media engine component captures authentication credentials or tokens and writes them to log files without adequate sanitization or encryption. This design flaw creates a persistent security risk where local attackers with access to the application directory can directly read these log files and extract sensitive authentication information. The vulnerability does not require network connectivity for exploitation since it operates entirely within the local file system context, making it particularly dangerous for environments where local privilege escalation or lateral movement is possible.
The operational impact of this vulnerability extends beyond simple credential theft, as the extracted authentication data could enable attackers to perform further malicious activities including unauthorized access to Cisco Webex services, session hijacking, or establishing persistent access to corporate communication platforms. The vulnerability affects authenticated local users who already have some level of access to the system, but the privilege escalation potential means that attackers could leverage the stolen credentials to access additional resources or services within the network. This creates a significant risk for organizations relying on Cisco Webex for business communications, as the compromise of a single client device could potentially expose broader network access if the stolen credentials are valid for multiple services.
Security professionals should consider this vulnerability in the context of ATT&CK framework tactic TA0006 (Credential Access) and technique T1074 (Data Staged), particularly focusing on the credential dumping and information gathering phases. The exploitation requires minimal technical skill and can be automated, making it attractive to threat actors seeking low-hanging fruit in enterprise environments. Organizations should implement immediate mitigations including restricting file system access to application directories, implementing proper log file permissions, and establishing monitoring for unauthorized access to sensitive directories. The vulnerability also highlights the importance of secure logging practices and proper input sanitization, as outlined in industry standards such as NIST SP 800-163 and ISO/IEC 27001 controls for information security management. Regular security assessments of logging mechanisms and access controls should be conducted to prevent similar vulnerabilities from persisting in other applications and systems.