CVE-2022-28753 in On-Premise Meeting Connector MMR
Summary
by MITRE • 08/11/2022
Zoom On-Premise Meeting Connector MMR before version 4.8.129.20220714 contains an improper access control vulnerability. As a result, a malicious actor can join a meeting which they are authorized to join without appearing to the other participants, can admit themselves into the meeting from the waiting room, and can become host and cause other meeting disruptions.
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Analysis
by VulDB Data Team • 09/10/2022
The Zoom On-Premise Meeting Connector MMR vulnerability represents a critical access control flaw that undermines the fundamental security model of enterprise meeting platforms. This vulnerability affects versions prior to 4.8.129.20220714 and exposes organizations to sophisticated unauthorized access scenarios that can compromise meeting integrity and participant privacy. The flaw specifically targets the meeting management system's authorization mechanisms, creating pathways for malicious actors to manipulate meeting participation and control structures without detection.
The technical implementation of this vulnerability stems from inadequate validation of user permissions and session management within the meeting connector's access control framework. When a malicious actor exploits this flaw, they can bypass normal meeting join restrictions and gain unauthorized access to meetings they should not be permitted to join. This improper access control condition allows attackers to appear invisible to other meeting participants while simultaneously gaining the ability to admit themselves into meetings from the waiting room. The vulnerability essentially creates a backdoor that circumvents the standard authentication and authorization protocols that should govern meeting participation.
From an operational impact perspective, this vulnerability enables attackers to assume host privileges within targeted meetings, providing them with extensive control over meeting parameters and participant management. The ability to join meetings without appearing to other participants creates a stealthy attack vector that can remain undetected for extended periods. This capability allows malicious actors to disrupt meetings through various means including removing participants, controlling audio and video settings, sharing inappropriate content, or conducting unauthorized recording operations that can compromise sensitive business communications.
The vulnerability aligns with CWE-285, which addresses improper authorization in access control systems, and demonstrates how insufficient validation of user privileges can lead to complete control over collaborative environments. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1190, which involves exploiting vulnerabilities in remote services to gain access to systems. The attack pattern enables threat actors to escalate privileges within meeting environments and conduct persistent surveillance or disruption activities that can significantly impact business operations and information security posture.
Organizations should immediately implement mitigations including updating to the patched version 4.8.129.20220714 or later, conducting thorough security assessments of their meeting connector configurations, and implementing additional monitoring controls for unusual meeting access patterns. Network segmentation strategies should be considered to limit exposure of meeting connector systems, while regular security audits should verify proper access control implementations. The vulnerability highlights the critical importance of maintaining up-to-date security patches for enterprise collaboration platforms and demonstrates how seemingly minor access control flaws can enable substantial security breaches in meeting environments.