CVE-2019-9621 Explained : Impact and Mitigation

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.

Understanding CVE-2019-9621

Zimbra Collaboration Suite versions earlier than 8.6 patch 13, versions earlier than 8.7.11 patch 10 in the 8.7.x series, and versions earlier than 8.8.10 patch 7 or 8.8.11 patch 3 in the 8.8.x series are affected by a Server-Side Request Forgery (SSRF) vulnerability.

What is CVE-2019-9621?

This CVE describes a vulnerability in Zimbra Collaboration Suite that allows an attacker to exploit the ProxyServlet component, leading to SSRF.

The Impact of CVE-2019-9621

Successful exploitation could allow an attacker to send crafted requests from the server, potentially leading to unauthorized access to internal resources.
Attackers could use SSRF to bypass security controls and interact with services on the same server or other back-end systems.

Technical Details of CVE-2019-9621

Zimbra Collaboration Suite is vulnerable to SSRF via the ProxyServlet component.

Vulnerability Description

The vulnerability allows attackers to perform SSRF attacks by manipulating the ProxyServlet component.

Affected Systems and Versions

Zimbra Collaboration Suite versions earlier than 8.6 patch 13
Versions earlier than 8.7.11 patch 10 in the 8.7.x series
Versions earlier than 8.8.10 patch 7 or 8.8.11 patch 3 in the 8.8.x series

Exploitation Mechanism

Attackers can exploit this vulnerability by sending specially crafted requests to the ProxyServlet component, tricking the server into making unauthorized requests.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks posed by CVE-2019-9621.

Immediate Steps to Take

Apply the necessary patches provided by Zimbra to address the SSRF vulnerability.
Monitor and restrict network access to prevent unauthorized requests.
Implement strong input validation to prevent malicious input.

Long-Term Security Practices

Regularly update and patch Zimbra Collaboration Suite to protect against known vulnerabilities.
Conduct security assessments and penetration testing to identify and address potential security weaknesses.

Patching and Updates

Ensure that Zimbra Collaboration Suite is kept up to date with the latest security patches to mitigate the SSRF vulnerability effectively.