CVE-2023-39199 in Zoom
Summary
by MITRE • 11/15/2023
Cryptographic issues with In-Meeting Chat for some Zoom clients may allow a privileged user to conduct an information disclosure via network access.
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Analysis
by VulDB Data Team • 09/19/2024
The vulnerability identified as CVE-2023-39199 represents a significant cryptographic weakness in Zoom's in-meeting chat functionality that affects certain client implementations. This issue specifically targets the encryption mechanisms used to protect chat communications during online meetings, creating a potential avenue for unauthorized access to sensitive meeting data. The flaw manifests when privileged users exploit weaknesses in the cryptographic protocols governing chat message transmission and storage, enabling them to intercept and access confidential information exchanged during virtual sessions.
The technical implementation of this vulnerability stems from inadequate cryptographic controls within Zoom's client-side chat processing. When users participate in meetings through affected Zoom clients, their chat messages may not be properly encrypted using industry-standard cryptographic algorithms or may employ weak key management practices. This cryptographic failure allows authenticated privileged users with network access to potentially decrypt and read chat communications that should remain confidential. The vulnerability specifically impacts the integrity and confidentiality of in-meeting chat data, which often contains sensitive business information, personal details, or proprietary discussions that participants expect to remain private.
From an operational perspective, this vulnerability creates substantial risk for organizations relying on Zoom for business communications, particularly those in regulated industries or sectors handling sensitive data. The impact extends beyond simple information disclosure to potentially compromise business continuity, intellectual property protection, and regulatory compliance. Organizations may face legal implications if confidential meeting discussions containing trade secrets, customer data, or strategic information are exposed through this cryptographic weakness. The privilege escalation aspect means that attackers need only obtain legitimate user credentials to exploit the vulnerability, making it particularly dangerous in environments where access controls may not be strictly enforced.
Security professionals should consider this vulnerability in the context of CWE-310, which addresses cryptographic issues, and align it with ATT&CK technique T1566 for credential harvesting and T1041 for data transmission. The mitigation strategy involves immediate deployment of Zoom client updates that address the cryptographic implementation flaws, along with implementing additional network monitoring to detect unauthorized access patterns. Organizations should also consider disabling in-meeting chat functionality until proper cryptographic fixes are verified, implementing network segmentation to limit access to meeting infrastructure, and conducting thorough security assessments of all meeting-related applications and services. Regular security audits should verify that cryptographic implementations meet current industry standards and that proper key management practices are maintained throughout the organization's communication infrastructure.