The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.1.1 sometimes allows unauthenticated users to execute commands.

Zimbra Collaboration before Kepler 9.0.0 Patch 38 GA allows DOM-based JavaScript injection in the Modern UI.

An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. XSS, with resultant session stealing, can occur via JavaScript code in a link (for a webmail redirection endpoint) within en email message, e.g., if a victim clicks on that link within Zimbra webmail.

An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. An attacker can send a PDF document through mail that contains malicious JavaScript. While previewing this file in webmail in the Chrome browser, the stored XSS payload is executed. (This has been mitigated by sanitising the JavaScript code present in a PDF document.)

An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. Through the help document endpoint in webmail, an attacker can inject JavaScript or HTML code that leads to cross-site scripting (XSS). (Adding an adequate message to avoid malicious code will mitigate this issue.)

An XSS issue was discovered in a web endpoint in Zimbra Collaboration (ZCS) before 10.0.4 via an unsanitized parameter. This is also fixed in 8.8.15 Patch 43 and 9.0.0 Patch 36.

An issue was discovered in Zimbra Collaboration (ZCS) before 10.0.4. An XSS issue can be exploited to access the mailbox of an authenticated user. This is also fixed in 8.8.15 Patch 43 and 9.0.0 Patch 36.

An issue was discovered in Zimbra Collaboration (ZCS) before 10.0.3. An attacker can gain access to a Zimbra account. This is also fixed in 9.0.0 Patch 35 and 8.8.15 Patch 42.

An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. Remote code execution can occur through ClientUploader by an authenticated admin user. An authenticated admin user can upload files through the ClientUploader utility, and traverse to any other directory for remote code execution.