An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.
An XSS vulnerability exists in the Webmail component of Zimbra Collaboration Suite before 8.8.15 Patch 11. It allows an attacker to inject executable JavaScript into the account name of a user's profile. The injected code can be reflected and executed when changing an e-mail signature.
Zimbra before 8.8.15 Patch 10 and 9.x before 9.0.0 Patch 3 allows remote code execution via an avatar file. There is potential abuse of /service/upload servlet in the webmail subsystem. A user can upload executable files (exe,sh,bat,jar) in the Contact section of the mailbox as an avatar image for a contact. A user will receive a "Corrupt File" error, but the file is still uploaded and stored locally in /opt/zimbra/data/tmp/upload/, leaving it open to possible remote execution.
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.
There is a Persistent XSS vulnerability in the briefcase component of Synacor Zimbra Collaboration Suite (ZCS) Zimbra Web Client (ZWC) 8.8.8 before 8.8.8 Patch 7 and 8.8.9 before 8.8.9 Patch 1.
An issue was discovered in Synacor Zimbra Collaboration Suite 8.6.x before 8.6.0 Patch 11, 8.7.x before 8.7.11 Patch 6, 8.8.x before 8.8.8 Patch 9, and 8.8.9 before 8.8.9 Patch 3. Account number enumeration is possible via inconsistent responses for specific types of authentication requests.
ZxChat (aka ZeXtras Chat), as used for zimbra-chat and zimbra-talk in Synacor Zimbra Collaboration Suite 8.7 and 8.8 and in other products, allows XXE attacks, as demonstrated by a crafted XML request to mailboxd.