CVE-2018-0110 in WebEx Meetings Server
Summary
by MITRE
A vulnerability in Cisco WebEx Meetings Server could allow an authenticated, remote attacker to access the remote support account even after it has been disabled via the web application. The vulnerability is due to a design flaw in Cisco WebEx Meetings Server, which would not disable access to specifically configured user accounts, even after access had been disabled in the web application. An attacker could exploit this vulnerability by connecting to the remote support account, even after it had been disabled at the web application level. An exploit could allow the attacker to modify server configuration and gain access to customer data. Cisco Bug IDs: CSCvg46741.
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Analysis
by VulDB Data Team • 02/01/2021
The vulnerability identified as CVE-2018-0110 represents a critical authorization flaw in Cisco WebEx Meetings Server that undermines the security posture of organizations relying on this platform for virtual meetings and collaboration. This design-level weakness specifically targets the remote support account functionality, creating a persistent security gap that allows authenticated attackers to maintain access even after administrative disablement through the web application interface. The vulnerability stems from insufficient account lifecycle management within the server architecture, where the system fails to properly synchronize the disablement state between the web application layer and the underlying authentication mechanisms. This misconfiguration creates a scenario where security controls implemented at the administrative interface become ineffective, as the backend systems continue to recognize and authenticate disabled accounts. The flaw directly violates fundamental security principles of least privilege and proper access control enforcement, as demonstrated by the Common Weakness Enumeration classification under CWE-284 which addresses improper access control mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized access, as successful exploitation enables attackers to perform privileged actions on the affected server infrastructure. Attackers can leverage the persistent access to modify critical server configurations, potentially compromising the entire meeting platform and affecting thousands of users within the organization. The ability to access customer data represents a severe data breach risk, particularly given the sensitive nature of meeting content and participant information typically handled by WebEx platforms. This vulnerability creates a persistent backdoor that could remain undetected for extended periods, allowing attackers to maintain long-term access and potentially escalate privileges through additional exploitation techniques. The attack vector requires only authenticated access to the web application, making it particularly dangerous as it can be exploited by individuals with legitimate user credentials who may have been granted access for support purposes but whose accounts are subsequently disabled.
Organizations affected by this vulnerability should implement immediate mitigations to address the persistent access issue, including manual verification of account states and implementation of additional access controls beyond the default web application interface. The recommended approach involves conducting comprehensive audits of all user accounts, particularly those with support privileges, to ensure that disablement actions are properly enforced at all system levels. Network segmentation and additional authentication controls should be implemented to limit the blast radius of potential exploitation. Security teams must also establish monitoring procedures to detect unauthorized access attempts to disabled accounts, utilizing log analysis and anomaly detection systems to identify suspicious activities. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate credentials, while also demonstrating the importance of proper account management and the dangers of incomplete access control implementation. The incident highlights the critical need for comprehensive security testing of account lifecycle management features and proper synchronization between different system layers to prevent such design flaws from creating persistent security weaknesses.