CVE-2019-9621 Scanner

Zimbra Collaboration Suite is a widely used email and collaboration platform for managing emails, calendars, contacts, and tasks by enterprise organizations. It is utilized by businesses and educational institutions to streamline communications and improve productivity. Zimbra is known for its robust, scalable, and extensible architecture, allowing for seamless integration with existing infrastructure. It provides various collaboration tools along with mobile and desktop client synchronization features. The platform supports a variety of deployment options, including on-premise and cloud. Users benefit from the suite's unified interface, enhancing team collaboration and communication while ensuring data security.

Server-Side-Request-Forgery (SSRF) is a vulnerability that allows attackers to send unauthorized requests from a vulnerable server, potentially manipulating and accessing internal systems. SSRF can be exploited to bypass firewalls, expose internal services, and access sensitive data. It poses a significant risk, particularly in cloud environments where internal network exposure can lead to broader attacks. The vulnerability typically arises from insufficient input validation in web applications that fetch remote content. Attackers craft specific requests to exploit the vulnerable endpoint, leveraging the server's permissions to reach otherwise inaccessible services. This can result in sensitive data leakage or other malicious activities.

The technical details of the vulnerability involve the misuse of the ProxyServlet component in Zimbra Collaboration Suite. An attacker leverages malformed XML containing crafted elements and entities to trigger the SSRF in the autodiscover endpoint. The exploitation allows attackers to access files or services on the company's internal network, which could include sensitive configuration files or other data. The vulnerability arises because the endpoint insufficiently validates the user inputs, including crafted XML payloads. Once the payload is processed, the SSRF can be executed, revealing unauthorized data access routes. This vulnerability requires immediate attention to prevent potential exploitation in environments utilizing vulnerable Zimbra versions.

If exploited, this vulnerability can allow attackers to gain unauthorized access to internal resources, leading to data exposure and potential network compromise. Malicious actors could leverage SSRF to move laterally within the network, access restricted data, or carry out further attacks using the server's privileges. The impact includes potential data breaches, loss of confidentiality, and service disruptions, which can substantially affect business operations and reputation. Companies using vulnerable versions of Zimbra should prioritize patching to mitigate these risks.

REFERENCES

• https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/http/zimbra_xxe_rce.rb
• https://nvd.nist.gov/vuln/detail/cve-2019-9621
• http://packetstormsecurity.com/files/153190/Zimbra-XML-Injection-Server-Side-Request-Forgery.html
• https://blog.tint0.com/2019/03/a-saga-of-code-executions-on-zimbra.html
• https://bugzilla.zimbra.com/show_bug.cgi?id=109127