: The server essentially becomes a tool for the attacker to send requests to other systems under the guise of the trusted Zimbra server. Impact and Risk
The vulnerability resides in improper sanitization of user-supplied input passed to the fmt parameter within certain Zimbra endpoints, such as:
: Attackers can map internal networks and identify other vulnerable services for further attacks. cve20207796 zimbra collaboration suite full
If the Zimbra server is hosted in cloud environments (e.g., AWS, Azure), the SSRF can be used to retrieve credentials from the cloud instance metadata service, potentially leading to full cloud environment compromise.
Actively monitor application logs for anomalous requests to internal services or suspicious DNS queries. : The server essentially becomes a tool for
This vulnerability contributed to multiple in late 2020 and early 2021, where attackers (including state-sponsored groups) targeted on-premise Zimbra instances in government, finance, and healthcare sectors.
Implement network-level restrictions to limit the Zimbra server’s outbound connections only to trusted destinations. Actively monitor application logs for anomalous requests to
Attackers can map the internal network infrastructure behind the firewall.
The Zimbra Collaboration Suite, a popular open-source email and collaboration platform, has been vulnerable to a critical security flaw, known as CVE-2020-7796. This vulnerability affects the full suite, exposing millions of users worldwide to potential cyber threats. In this article, we will explore the details of the vulnerability, its impact, and the necessary steps to mitigate the risks.
Before diving into the details, here is a quick overview of the key attributes of CVE-2020-7796:
At its core, the vulnerability is a classic case of insufficient input validation. The Zimbra server blindly trusted a URL provided by a remote, unauthenticated attacker and initiated a request to that location. The server executed this request with its own privileges, effectively acting as an unwitting proxy.