Recent research has uncovered a security glitch in Zoom’s screen sharing feature that could inadvertently expose sensitive information to participants during video calls. This vulnerability, designated as CVE-2021-28133, is notable as it remains unpatched, enabling the possibility of revealing contents from applications not actively being shared, albeit for only brief moments.
The vulnerability arises from Zoom’s screen sharing functionality, which allows users to share their entire desktop or specific applications. However, the issue originates when a secondary application overlays the shared content; this can lead to the transient exposure of sensitive information from the unshared application. According to SySS researchers Michael Strametz and Matthias Deeg, “When a Zoom user shares a specific application window via the ‘share screen’ functionality, other meeting participants can briefly see contents of other application windows which were not explicitly shared.”
The flaw was examined in Zoom versions 5.4.3 and 5.5.4 on both Windows and Linux operating systems. Researchers disclosed the security issue to Zoom on December 2, 2020. Interestingly, despite being reported over three months ago, the lack of a fix may be a result of the inherent challenges associated with exploiting this vulnerability in real-world scenarios.
While the window for exploiting this issue may seem limited, the potential consequences could be significant. Malicious participants in a Zoom meeting can utilize screen capture tools to record meetings, effectively gaining access to private information that may briefly appear during the session. Thus, the sensitivity of the data involved has prompted concerns among cybersecurity experts.
In a response to inquiries, a spokesperson for Zoom emphasized the company’s commitment to addressing security vulnerabilities. “Zoom takes all reports of security vulnerabilities seriously,” the representative stated. “We are aware of this issue and are working to resolve it.”
As business owners navigate an increasingly complex digital landscape, understanding vulnerabilities such as CVE-2021-28133 is crucial. The MITRE ATT&CK framework can help contextualize the potential tactics and techniques involved in such incidents, highlighting areas like initial access and privilege escalation that may facilitate similar exposures. It is essential for organizations to remain vigilant and proactive in securing digital communications, especially in the context of remote work and virtual collaboration.
