CVE-2020-8633 : Security Advisory and Response

An issue was discovered in Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7. When grantors revoked a shared calendar in Outlook, the calendar stayed mounted and accessible.

Understanding CVE-2020-8633

This CVE identifies a vulnerability in Zimbra Collaboration Suite (ZCS) that allows shared calendars to remain accessible in Outlook after being revoked.

What is CVE-2020-8633?

The issue in ZCS before 8.8.15 Patch 7 enables shared calendars to stay mounted and accessible even after revocation by grantors in Outlook.

The Impact of CVE-2020-8633

This vulnerability could lead to unauthorized access to sensitive calendar information, potentially compromising user privacy and confidentiality.

Technical Details of CVE-2020-8633

This section provides more technical insights into the vulnerability.

Vulnerability Description

The flaw in ZCS allows shared calendars to remain accessible in Outlook despite being revoked, posing a security risk.

Affected Systems and Versions

Product: Zimbra Collaboration Suite (ZCS)
Versions affected: Before 8.8.15 Patch 7

Exploitation Mechanism

The vulnerability can be exploited by revoking access to a shared calendar in Outlook, yet the calendar remains accessible.

Mitigation and Prevention

To address CVE-2020-8633, follow these mitigation steps:

Immediate Steps to Take

Apply the latest patch (8.8.15 Patch 7) to ZCS.
Monitor calendar access and revoke permissions as needed.

Long-Term Security Practices

Regularly review and update access controls for shared resources.
Educate users on the importance of revoking access appropriately.

Patching and Updates

Ensure timely installation of security patches and updates for ZCS to prevent exploitation of known vulnerabilities.