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.
Cross-site request forgery (CSRF) vulnerability in the login form in Zimbra Collaboration Suite (aka ZCS) before 8.6.0 Patch 10, 8.7.x before 8.7.11 Patch 2, and 8.8.x before 8.8.8 Patch 1 allows remote attackers to hijack the authentication of unspecified victims by leveraging failure to use a CSRF token.