CVE-2018-0436 in WebEx Teams
Summary
by MITRE
A vulnerability in Cisco Webex Teams, formerly Cisco Spark, could allow an authenticated, remote attacker to view and modify data for an organization other than their own organization. The vulnerability exists because the affected software performs insufficient checks for associations between user accounts and organization accounts. An attacker who has administrator or compliance officer privileges for one organization account could exploit this vulnerability by using those privileges to view and modify data for another organization account. No customer data was impacted by this vulnerability.
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Analysis
by VulDB Data Team • 03/30/2020
The vulnerability identified as CVE-2018-0436 resides within Cisco Webex Teams, formerly known as Cisco Spark, representing a critical authorization bypass flaw that undermines the fundamental security boundaries between organizational entities within the platform. This weakness stems from inadequate validation mechanisms that fail to properly enforce associations between user accounts and their respective organizational accounts, creating a pathway for privilege escalation attacks. The vulnerability specifically targets the software's access control implementation, where proper segregation of duties between organizations is not adequately maintained during authentication and authorization processes.
The technical flaw manifests when an authenticated attacker with administrative or compliance officer privileges for one organization attempts to access resources belonging to a different organization. This occurs because the system does not perform sufficient checks to validate that the requesting user has legitimate access rights to the target organization's data. The vulnerability operates at the application layer and requires minimal prerequisites, as the attacker only needs valid credentials for one organization to potentially compromise data belonging to another organization. This type of flaw aligns with CWE-285, which addresses improper authorization in software applications, and represents a classic case of insufficient access control validation.
The operational impact of this vulnerability extends beyond simple data exposure, as it enables both read and write operations across organizational boundaries, potentially allowing attackers to modify critical configuration settings, user permissions, or sensitive organizational data. Attackers could leverage this vulnerability to gain unauthorized access to confidential information, manipulate organizational policies, or disrupt business operations by modifying user accounts and access controls. The risk is particularly elevated for organizations that rely heavily on Cisco Webex Teams for business communications, as the compromise of one organization's administrative account could potentially lead to cascading effects across multiple organizational entities within the same platform instance.
Organizations should implement immediate mitigations including enhanced monitoring of administrative account activities, implementation of multi-factor authentication for privileged users, and regular review of access control policies. The vulnerability demonstrates the importance of maintaining strict organizational boundaries even within unified communication platforms, as highlighted by ATT&CK technique T1078 which addresses valid accounts and privilege escalation. Security teams should also consider implementing network segmentation controls and limiting the scope of administrative privileges to minimize potential impact if such vulnerabilities are exploited. While no customer data was reported as directly impacted by this specific vulnerability, the potential for data exposure and modification across organizational boundaries makes this a critical concern for enterprises relying on Cisco Webex Teams for their collaboration infrastructure.