Cve20207796 Zimbra Collaboration Suite Full _best_ ❲ORIGINAL❳

POST /service/extension/UserServlet HTTP/1.1 Host: target.zimbra.com Content-Type: application/x-www-form-urlencoded file=../../../../../../../../opt/zimbra/bin/zmcontrol&cmd=status&ext=foo

While 2020 saw several high-profile vulnerabilities in Zimbra (notably CVE-2020-27988 and CVE-2020-28016), one flaw stands out for its severity and the chilling simplicity of its exploitation: . This vulnerability, rated Critical (CVSS 9.8) , allows an unauthenticated attacker to achieve full Remote Code Execution (RCE) on the underlying Zimbra server, leading to complete compromise of the email infrastructure. cve20207796 zimbra collaboration suite full

The flaw resides in how the servlet validates (or fails to validate) the file parameter. In a typical request: POST /service/extension/UserServlet HTTP/1

But the actual working exploit uses the ProxyServlet to access the local Mailboxd service’s admin interface, which in turn allows command execution via a crafted soap request. In a typical request: But the actual working

| CVE | Type | Auth Required | Impact | |-----|------|---------------|--------| | CVE-2020-27988 | Path traversal to mail read | No | Unauthenticated mail fetch | | CVE-2020-28016 | SSRF via proxy | No | Internal port scanning, limited info leak | | | RCE via extension/proxy | No | Full system compromise |

Introduction In the landscape of enterprise email and collaboration tools, Zimbra Collaboration Suite (ZCS) has long been a favorite for organizations seeking an alternative to Microsoft Exchange. Its robust feature set, open-source core, and scalability make it a prime target for nation-state actors and ransomware gangs alike.