CVE-2022-28763 is a high-severity vulnerability affecting the Zoom Client for Meetings across multiple platforms including Android, iOS, Linux, macOS, and Windows. The root cause is improper input validation (CWE-20) in the URL parsing logic of the Zoom client prior to version 5.12.2. Specifically, when a user opens a maliciously crafted Zoom meeting URL, the client may incorrectly parse the URL and redirect the connection to an arbitrary network address controlled by an attacker. This flaw can be exploited without any privileges or authentication, requiring only that the user interacts by opening the malicious link. The vulnerability impacts confidentiality, integrity, and availability, as it can lead to session takeovers and potentially other follow-on attacks such as man-in-the-middle interception or unauthorized access to internal network resources. The CVSS 3.1 base score is 8.8, reflecting the network attack vector, low attack complexity, no privileges required, but user interaction needed, and high impact on confidentiality, integrity, and availability. Although no known exploits in the wild have been reported, the widespread use of Zoom in corporate, educational, and governmental environments makes this vulnerability a significant risk. The vulnerability affects all major operating systems supported by Zoom, increasing the scope of affected systems globally. The improper input validation allows attackers to craft URLs that bypass intended restrictions, potentially redirecting users to malicious servers or internal IP addresses, enabling session hijacking or data exfiltration. This vulnerability underscores the importance of robust URL parsing and validation in client applications that handle external input.

For European organizations, the impact of CVE-2022-28763 is considerable due to the extensive reliance on Zoom for remote collaboration, especially post-pandemic. Exploitation could lead to unauthorized access to sensitive meetings, confidential business discussions, and intellectual property leakage. Session takeovers could allow attackers to impersonate legitimate users, disrupt meetings, or inject malicious content. The vulnerability also poses risks to critical infrastructure operators and government agencies using Zoom, potentially exposing sensitive operational information. The cross-platform nature of the vulnerability means that organizations with diverse device ecosystems are at risk. Furthermore, the ability to redirect connections to arbitrary network addresses could facilitate lateral movement within corporate networks if internal addresses are targeted, increasing the risk of broader compromise. The high CVSS score and the ease of exploitation through social engineering (sending malicious meeting URLs) amplify the threat level. European organizations in sectors such as finance, healthcare, government, and education are particularly vulnerable due to the sensitivity of their communications and regulatory requirements around data protection (e.g., GDPR).

1. Immediate upgrade: Organizations should prioritize upgrading all Zoom clients to version 5.12.2 or later, where this vulnerability is patched. 2. URL handling policies: Implement endpoint security controls that detect and block suspicious or malformed Zoom URLs before they reach end users, such as email gateway filters or web proxies with URL inspection capabilities tailored to Zoom meeting links. 3. User awareness training: Educate users to be cautious about clicking on Zoom meeting links from untrusted sources and to verify meeting invitations through secondary channels. 4. Network segmentation: Restrict Zoom client access to internal network resources where possible, limiting the impact of redirected connections to arbitrary internal addresses. 5. Monitoring and detection: Deploy network monitoring to detect unusual Zoom client connection patterns or unexpected network address resolutions that could indicate exploitation attempts. 6. Multi-factor authentication (MFA): While not directly preventing this vulnerability, enforcing MFA on Zoom accounts can reduce the impact of session takeovers by requiring additional verification. 7. Incident response readiness: Prepare to respond to potential session hijacking incidents by having procedures to quickly revoke compromised credentials and notify affected users. These mitigations go beyond generic advice by focusing on controlling the attack vector (malicious URLs), enhancing user vigilance, and limiting network exposure.