CVE CyberSecurity Database News

CVE-2023-37580 - Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41: XSS Vulnerability in Zimbra Classic Web Client

Poster -

In this long read post, we will cover a security vulnerability registered under the code CVE-2023-37580. Zimbra Collaboration (ZCS) 8.x is affected by this XSS vulnerability in the Classic Web Client. The Zimbra Collaboration Suite (ZCS) is a popular open-source email and collaboration platform that offers secure email, file-sharing, and calendar functionality. It is widely used by organizations and service providers around the world, but unfortunately, it has been found to have a security vulnerability in versions before 8.8.15 Patch 41.

The Issue: Cross-Site Scripting (XSS) Vulnerability

Cross-Site Scripting, or XSS, is a common web application security vulnerability that allows an attacker to inject malicious scripts into web pages viewed by other users. This vulnerability leaves users susceptible to various threats such as account hijacking, click-jacking, and potential data theft.

In the case of Zimbra Collaboration (ZCS) 8.x, XSS vulnerabilities have been discovered specifically in the Zimbra Classic Web Client. This means that attackers could potentially exploit this XSS flaw by injecting malicious code into web pages managed by affected versions of the Zimbra platform.

The Vulnerable Code Snippet

The following snippet of code illustrates the problematic functionality, which is not sanitizing user-input correctly and, thus, allows for the insertion of malicious scripts:

<head>
    <script src="https://yourzimbraserver.com/opac.js"></script>;
</head>
<body>
    <form>
        <input id="search">
        <button>Search</button>
    </form>
    <div id="result"></div>

    <script>
        document.querySelector("form").addEventListener("submit", function (event) {
            event.preventDefault();
            var searchTerm = document.getElementById("search").value;
            var element = document.getElementById("result");
            element.innerHTML = searchTerm;
        });
    </script>
</body>

The details of this vulnerability can be found in the following references

- CVE-2023-37580 - National Vulnerability Database (NVD)
- Zimbra Security Advisory - Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41
- Synacor Bugs - ZBUG-280: Cross-Site Scripting Issue in Zimbra Classic Web Client

Exploit Details

To exploit this vulnerability, an attacker could craft a link containing malicious JavaScript code and send it to victims using the affected Zimbra platform. The malicious JavaScript would execute in the victims' browsers upon visiting the link, possibly leading to unauthorized access to their accounts or other sensitive information.

https://yourzimbraserver.com/zimbra/classic?search=<script>alert('XSS');</script>;

Upon clicking this link, the user would be presented with an alert from the attacker's script, demonstrating the successful execution of the XSS vulnerability.

## Mitigation

To protect from this vulnerability, users running Zimbra Collaboration (ZCS) 8.x should update to version 8.8.15 Patch 41 or later, which contains the necessary security fixes. Additionally, it is recommended to review and sanitize all user input in the web application to prevent any future XSS vulnerabilities.

In conclusion, CVE-2023-37580 is a serious XSS vulnerability found in Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 in the Classic Web Client. Proper security measures and updates should be taken to ensure the safety of users and organizations utilizing the affected Zimbra platform.

Timeline

Published on: 07/31/2023 16:15:00 UTC
Last modified on: 08/04/2023 17:10:00 UTC