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.
mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, as demonstrated by Autodiscover/Autodiscover.xml.
Zimbra Collaboration Suite before 8.6 patch 13, 8.7.x before 8.7.11 patch 10, and 8.8.x before 8.8.10 patch 7 or 8.8.x before 8.8.11 patch 3 allows SSRF via the ProxyServlet component.